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Java에서 배열을 정렬하는 방법

정렬은 목록이나 배열의 요소를 특정 순서로 정렬하는 방법입니다. 순서는 오름차순 또는 내림차순일 수 있습니다. 그만큼 숫자 그리고 사전식 (알파벳순) 순서는 널리 사용되는 순서입니다.

숫자로 된 알파벳

이 섹션에서는 다음 내용을 학습합니다. 배열을 정렬하는 방법 ~에 자바 ~에 오름차순 그리고 내림차순 이용해서 주문하세요 종류() 방법과 sort() 메소드를 사용하지 않고 . 이와 함께 우리는 또한 배울 것입니다 하위 배열을 정렬하는 방법 ~에 자바 .

배열을 오름차순으로 정렬

그만큼 오름차순 요소를 가장 낮은 순서에서 가장 높은 순서로 정렬합니다. 그것은 또한로 알려져 있습니다 자연의 질서 또는 숫자 순서 . 다음과 같은 방법으로 정렬을 수행할 수 있습니다.

  • sort() 메서드 사용
  • 방법을 사용하지 않고
    • for 루프 사용
    • 사용자 정의 방법 사용

sort() 메서드 사용

자바에서는 배열 에 정의된 클래스입니다.java.util제공하는 패키지 종류() 배열을 오름차순으로 정렬하는 방법. 그것은 사용한다 듀얼 피벗 퀵소트 알고리즘 정렬용. 그 복잡성은 O(n로그(n)) . 이것은 공전 구문 분석하는 메소드 정렬 매개변수로 사용되며 아무것도 반환하지 않습니다. 클래스 이름을 사용하여 직접 호출할 수 있습니다. int, float, double, long, char, byte 유형의 배열을 허용합니다.

통사론: 

 public static void sort(int[] a)

어디 ㅏ 짧은 배열입니다.

참고: Arrays 클래스와 마찬가지로 Collections 클래스도 배열을 정렬하는 sort() 메서드를 제공합니다. 그러나 그들 사이에는 차이점이 있습니다. Arrays 클래스의 sort() 메서드는 기본 유형에 대해 작동하는 반면 Collections 클래스의 sort() 메서드는 LinkedList, ArrayList 등과 같은 컬렉션 개체에 대해 작동합니다.

Arrays 클래스의 sort() 메서드를 사용하여 배열을 정렬해 보겠습니다.

다음 프로그램에서는 정수 유형의 배열을 정의했습니다. 그런 다음 Arrays 클래스의 sort() 메서드를 호출하고 정렬할 배열을 구문 분석합니다. 정렬된 배열을 인쇄하기 위해 for 루프를 사용했습니다.

SortArrayExample1.java 

 import java.util.Arrays; public class SortArrayExample1 { public static void main(String[] args) { //defining an array of integer type int [] array = new int [] {90, 23, 5, 109, 12, 22, 67, 34}; //invoking sort() method of the Arrays class Arrays.sort(array); System.out.println(&apos;Elements of array sorted in ascending order: &apos;); //prints array using the for loop for (int i = 0; i <array.length; i++) { system.out.println(array[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Array elements in ascending order: 5 12 22 23 34 67 90 109 </pre> <p>In the above program, we can also use the toSting() method of the Arrays class to print the array, as shown in the following statement. It returns a string representation of the specified array.</p> <pre> System.out.printf(Arrays.toString(array)); </pre> <h3>Without Using the Method</h3> <h3>Using the for Loop</h3> <p>In the following example, we have initialized an array of integer type and sort the array in ascending order.</p> <p> <strong>SortArrayExample2.java</strong> </p> <pre> public class SortArrayExample2 { public static void main(String[] args) { //creating an instance of an array int[] arr = new int[] {78, 34, 1, 3, 90, 34, -1, -4, 6, 55, 20, -65}; System.out.println(&apos;Array elements after sorting:&apos;); //sorting logic for (int i = 0; i <arr.length; i++) { for (int j="i" + 1; arr[j]) tmp="arr[i];" arr[i]="arr[j];" arr[j]="tmp;" } prints the sorted element of array system.out.println(arr[i]); < pre> <p> <strong>Output:</strong> </p> <pre> Array elements after sorting: -65 -4 -1 1 3 6 20 34 34 55 78 90 </pre> <h3>Using the User Defined Method</h3> <p>In the following example, we have defined a method named <strong>sortArray()</strong> that contains the logic to sort an array in natural order.</p> <p> <strong>SortArrayExample3.java</strong> </p> <pre> public class SortArrayExample3 { public static void main(String[] args) { int i; //initializing an array int array[] = {12, 45, 1, -1, 0, 4, 56, 23, 89, -21, 56, 27}; System.out.print(&apos;Array elements before sorting: 
&apos;); for(i = 0; i <array.length; i++) system.out.println(array[i]); invoking user defined method sortarray(array, array.length); system.out.print('array elements after sorting: 
'); accessing of the sorted array for(i="0;" i <array.length; { } to sort an in ascending order private static void sortarray(int array[], int n) for (int <n; j="i;" a="array[i];" while ((j> 0) &amp;&amp; (array[j-1] &gt; a)) //returns true when both conditions are true { array[j] = array[j-1]; j--; } array[j] = a; } } } </array.length;></pre> <p> <strong>Output:</strong> </p> <pre> Array elements before sorting: 12 45 1 -1 0 4 56 23 89 -21 56 27 Array elements after sorting: -21 -1 0 1 4 12 23 27 45 56 56 89 </pre> <h2>Sort Array in Descending Order</h2> <p>The <strong>descending order</strong> arranges the elements in the highest to lowest order. We can perform sorting in the following ways:</p> <ul> <li>Using the <strong>reverseOrder()</strong> Method</li> <li>Without using the method <ul> <li>Using the <strong>for</strong> Loop</li> <li>Using the <strong>User Defined</strong> Method</li> </ul></li> </ul> <h3>Using the reverseOrder() Method</h3> <p> <a href="/java-collections-class">Java <strong>Collections</strong> class</a> provides the <strong>reverseOrder()</strong> method to sort the array in reverse-lexicographic order. It is a static method, so we can invoke it directly by using the class name. It does not parse any parameter. It returns a <strong>comparator</strong> that imposes the reverse of the natural ordering (ascending order).</p> <p>It means that the array sorts elements in the ascending order by using the sort() method, after that the reverseOrder() method reverses the natural ordering, and we get the sorted array in descending order.</p> <p> <strong>Syntax:</strong> </p> <pre> public static Comparator reverseOrder() </pre> <p>Suppose, a[] is an array to be sort in the descending order. We will use the reverseOrder() method in the following way:</p> <pre> Arrays.sort(a, Collections.reverseOrder()); </pre> <p>Let&apos;s sorts an array in the descending order.</p> <p>In the following program, a point to be noticed that we have defined an array as <strong>Integer</strong> . Because the reverseOrder() method does not work for the primitive data type.</p> <p> <strong>SortArrayExample4.java</strong> </p> <pre> import java.util.Arrays; import java.util.Collections; public class SortArrayExample4 { public static void main(String[] args) { Integer [] array = {23, -9, 78, 102, 4, 0, -1, 11, 6, 110, 205}; // sorts array[] in descending order Arrays.sort(array, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(array)); } } </pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: [205, 110, 102, 78, 23, 11, 6, 4, 0, -1, -9] </pre> <p>Let&apos;s see another program that sorts array elements in alphabetical order.</p> <p> <strong>SortArrayExample5.java</strong> </p> <pre> import java.util.Arrays; import java.util.Collections; public class SortArrayExample5 { public static void main(String[] args) { String [] strarray = {&apos;Mango&apos;, &apos;Apple&apos;, &apos;Grapes&apos;, &apos;Papaya&apos;, &apos;Pineapple&apos;, &apos;Banana&apos;, &apos;Orange&apos;}; // sorts array[] in descending order Arrays.sort(strarray, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(strarray)); } } </pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: [Papaya, Pineapple, Orange, Mango, Grapes, Banana, Apple] </pre> <h3>Without Using the Method</h3> <h3>Using the for Loop</h3> <p>In the following example, we have initialized an integer array and perform sorting in descending order.</p> <p> <strong>SortArrayExample6.java</strong> </p> <pre> public class SortArrayExample6 { public static void main(String[] args) { int temp; //initializing an array int a[]={12,5,56,-2,32,2,-26,9,43,94,-78}; for (int i = 0; i <a.length; i++) { for (int j="i" + 1; < a.length; j++) if (a[i] a[j]) temp="a[i];" a[i]="a[j];" a[j]="temp;" } system.out.println('array elements in descending order:'); accessing element of the array i="0;" - system.out.println(a[i]); pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: 94 56 43 32 12 9 5 2 -2 -26 -78 </pre> <h3>Using the User Defined Method</h3> <p> <strong>SortArrayExample7.java</strong> </p> <pre> import java.util.Scanner; public class SortArrayExample7 { public static void main(String[] args) { int n, temp; Scanner s = new Scanner(System.in); System.out.print(&apos;Enter the number of elements: &apos;); n = s.nextInt(); int a[] = new int[n]; System.out.println(&apos;Enter the elements of the array: &apos;); for (int i = 0; i <n; i++) { a[i]="s.nextInt();" } for (int i="0;" < n; j="i" + 1; j++) if (a[i] a[j]) temp="a[i];" a[j]="temp;" system.out.println('array elements in descending order:'); n - system.out.println(a[i]); system.out.print(a[n 1]); pre> <p> <strong>Output:</strong> </p> <pre> Enter the number of elements: 7 Enter the elements of the array: 12 5 56 -2 32 2 -26 Array elements in descending order: 56 32 12 5 2 -2 -26 </pre> <h2>How to Sort Subarray</h2> <p>An array derived from the array is known as <strong>subarray</strong> . Suppose, <strong>a[]</strong> is an array having the elements [12, 90, 34, 2, 45, 3, 22, 18, 5, 78] and we want to sort array elements from 34 to 18. It will sort the subarray <strong>[34, 2, 45, 3, 22, 18]</strong> and keep the other elements as it is.</p> <p>To sort the subarray, the Arrays class provides the static method named <strong>sort()</strong> . It sorts the specified range of the array into ascending order. We can also sort the array of type <strong>long, double, float, char, byte,</strong> etc.</p> <p> <strong>Syntax:</strong> </p> <pre> public static void sort(int[] a, int fromIndex, int toIndex) </pre> <p>The method parses the following three parameters:</p> <ul> <tr><td>a:</td> An array to be sort. </tr><tr><td>fromIndex:</td> The index of the first element of the subarray. It participates in the sorting. </tr><tr><td>toIndex:</td> The index of the last element of the subarray. It does not participate in the sorting. </tr></ul> <p>If formIndex is equal to the toIndex, the range to be sorted is empty. It throws IllegalArgumentException if <strong>fomIndex is greater than toIndex</strong> . It also throws ArrayIndexOutOfBoundsException if <strong>fromIndex a.length</strong> .</p> <p>Let&apos;s sort a subarray through a Java program.</p> <p> <strong>SortSubarrayExample.java</strong> </p> <pre> import java.util.Arrays; public class SortSubarrayExample { public static void main(String[] args) { //defining an array int[] a = {12, 90, 34, 2, 45, 3, 22, 18, 5, 78}; // sorts subarray form index 2 to 7 Arrays.sort(a, 2, 7); //prints array using the for loop for (int i = 0; i <a.length; i++) { system.out.println(a[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Sorted Subarray: 12 90 2 3 22 34 45 18 5 78 </pre> <hr></a.length;></pre></n;></pre></a.length;></pre></arr.length;></pre></array.length;>

위 프로그램에서는 다음 명령문과 같이 Arrays 클래스의 toSting() 메서드를 사용하여 배열을 인쇄할 수도 있습니다. 지정된 배열의 문자열 표현을 반환합니다.

 System.out.printf(Arrays.toString(array));

방법을 사용하지 않고

for 루프 사용

다음 예제에서는 정수형 배열을 초기화하고 오름차순으로 정렬했습니다.

SortArrayExample2.java 

 public class SortArrayExample2 { public static void main(String[] args) { //creating an instance of an array int[] arr = new int[] {78, 34, 1, 3, 90, 34, -1, -4, 6, 55, 20, -65}; System.out.println(&apos;Array elements after sorting:&apos;); //sorting logic for (int i = 0; i <arr.length; i++) { for (int j="i" + 1; arr[j]) tmp="arr[i];" arr[i]="arr[j];" arr[j]="tmp;" } prints the sorted element of array system.out.println(arr[i]); < pre> <p> <strong>Output:</strong> </p> <pre> Array elements after sorting: -65 -4 -1 1 3 6 20 34 34 55 78 90 </pre> <h3>Using the User Defined Method</h3> <p>In the following example, we have defined a method named <strong>sortArray()</strong> that contains the logic to sort an array in natural order.</p> <p> <strong>SortArrayExample3.java</strong> </p> <pre> public class SortArrayExample3 { public static void main(String[] args) { int i; //initializing an array int array[] = {12, 45, 1, -1, 0, 4, 56, 23, 89, -21, 56, 27}; System.out.print(&apos;Array elements before sorting: 
&apos;); for(i = 0; i <array.length; i++) system.out.println(array[i]); invoking user defined method sortarray(array, array.length); system.out.print(\'array elements after sorting: 
\'); accessing of the sorted array for(i="0;" i <array.length; { } to sort an in ascending order private static void sortarray(int array[], int n) for (int <n; j="i;" a="array[i];" while ((j> 0) &amp;&amp; (array[j-1] &gt; a)) //returns true when both conditions are true { array[j] = array[j-1]; j--; } array[j] = a; } } } </array.length;></pre> <p> <strong>Output:</strong> </p> <pre> Array elements before sorting: 12 45 1 -1 0 4 56 23 89 -21 56 27 Array elements after sorting: -21 -1 0 1 4 12 23 27 45 56 56 89 </pre> <h2>Sort Array in Descending Order</h2> <p>The <strong>descending order</strong> arranges the elements in the highest to lowest order. We can perform sorting in the following ways:</p> <ul> <li>Using the <strong>reverseOrder()</strong> Method</li> <li>Without using the method <ul> <li>Using the <strong>for</strong> Loop</li> <li>Using the <strong>User Defined</strong> Method</li> </ul></li> </ul> <h3>Using the reverseOrder() Method</h3> <p> <a href="/java-collections-class">Java <strong>Collections</strong> class</a> provides the <strong>reverseOrder()</strong> method to sort the array in reverse-lexicographic order. It is a static method, so we can invoke it directly by using the class name. It does not parse any parameter. It returns a <strong>comparator</strong> that imposes the reverse of the natural ordering (ascending order).</p> <p>It means that the array sorts elements in the ascending order by using the sort() method, after that the reverseOrder() method reverses the natural ordering, and we get the sorted array in descending order.</p> <p> <strong>Syntax:</strong> </p> <pre> public static Comparator reverseOrder() </pre> <p>Suppose, a[] is an array to be sort in the descending order. We will use the reverseOrder() method in the following way:</p> <pre> Arrays.sort(a, Collections.reverseOrder()); </pre> <p>Let&apos;s sorts an array in the descending order.</p> <p>In the following program, a point to be noticed that we have defined an array as <strong>Integer</strong> . Because the reverseOrder() method does not work for the primitive data type.</p> <p> <strong>SortArrayExample4.java</strong> </p> <pre> import java.util.Arrays; import java.util.Collections; public class SortArrayExample4 { public static void main(String[] args) { Integer [] array = {23, -9, 78, 102, 4, 0, -1, 11, 6, 110, 205}; // sorts array[] in descending order Arrays.sort(array, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(array)); } } </pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: [205, 110, 102, 78, 23, 11, 6, 4, 0, -1, -9] </pre> <p>Let&apos;s see another program that sorts array elements in alphabetical order.</p> <p> <strong>SortArrayExample5.java</strong> </p> <pre> import java.util.Arrays; import java.util.Collections; public class SortArrayExample5 { public static void main(String[] args) { String [] strarray = {&apos;Mango&apos;, &apos;Apple&apos;, &apos;Grapes&apos;, &apos;Papaya&apos;, &apos;Pineapple&apos;, &apos;Banana&apos;, &apos;Orange&apos;}; // sorts array[] in descending order Arrays.sort(strarray, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(strarray)); } } </pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: [Papaya, Pineapple, Orange, Mango, Grapes, Banana, Apple] </pre> <h3>Without Using the Method</h3> <h3>Using the for Loop</h3> <p>In the following example, we have initialized an integer array and perform sorting in descending order.</p> <p> <strong>SortArrayExample6.java</strong> </p> <pre> public class SortArrayExample6 { public static void main(String[] args) { int temp; //initializing an array int a[]={12,5,56,-2,32,2,-26,9,43,94,-78}; for (int i = 0; i <a.length; i++) { for (int j="i" + 1; < a.length; j++) if (a[i] a[j]) temp="a[i];" a[i]="a[j];" a[j]="temp;" } system.out.println(\'array elements in descending order:\'); accessing element of the array i="0;" - system.out.println(a[i]); pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: 94 56 43 32 12 9 5 2 -2 -26 -78 </pre> <h3>Using the User Defined Method</h3> <p> <strong>SortArrayExample7.java</strong> </p> <pre> import java.util.Scanner; public class SortArrayExample7 { public static void main(String[] args) { int n, temp; Scanner s = new Scanner(System.in); System.out.print(&apos;Enter the number of elements: &apos;); n = s.nextInt(); int a[] = new int[n]; System.out.println(&apos;Enter the elements of the array: &apos;); for (int i = 0; i <n; i++) { a[i]="s.nextInt();" } for (int i="0;" < n; j="i" + 1; j++) if (a[i] a[j]) temp="a[i];" a[j]="temp;" system.out.println(\'array elements in descending order:\'); n - system.out.println(a[i]); system.out.print(a[n 1]); pre> <p> <strong>Output:</strong> </p> <pre> Enter the number of elements: 7 Enter the elements of the array: 12 5 56 -2 32 2 -26 Array elements in descending order: 56 32 12 5 2 -2 -26 </pre> <h2>How to Sort Subarray</h2> <p>An array derived from the array is known as <strong>subarray</strong> . Suppose, <strong>a[]</strong> is an array having the elements [12, 90, 34, 2, 45, 3, 22, 18, 5, 78] and we want to sort array elements from 34 to 18. It will sort the subarray <strong>[34, 2, 45, 3, 22, 18]</strong> and keep the other elements as it is.</p> <p>To sort the subarray, the Arrays class provides the static method named <strong>sort()</strong> . It sorts the specified range of the array into ascending order. We can also sort the array of type <strong>long, double, float, char, byte,</strong> etc.</p> <p> <strong>Syntax:</strong> </p> <pre> public static void sort(int[] a, int fromIndex, int toIndex) </pre> <p>The method parses the following three parameters:</p> <ul> <tr><td>a:</td> An array to be sort. </tr><tr><td>fromIndex:</td> The index of the first element of the subarray. It participates in the sorting. </tr><tr><td>toIndex:</td> The index of the last element of the subarray. It does not participate in the sorting. </tr></ul> <p>If formIndex is equal to the toIndex, the range to be sorted is empty. It throws IllegalArgumentException if <strong>fomIndex is greater than toIndex</strong> . It also throws ArrayIndexOutOfBoundsException if <strong>fromIndex a.length</strong> .</p> <p>Let&apos;s sort a subarray through a Java program.</p> <p> <strong>SortSubarrayExample.java</strong> </p> <pre> import java.util.Arrays; public class SortSubarrayExample { public static void main(String[] args) { //defining an array int[] a = {12, 90, 34, 2, 45, 3, 22, 18, 5, 78}; // sorts subarray form index 2 to 7 Arrays.sort(a, 2, 7); //prints array using the for loop for (int i = 0; i <a.length; i++) { system.out.println(a[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Sorted Subarray: 12 90 2 3 22 34 45 18 5 78 </pre> <hr></a.length;></pre></n;></pre></a.length;></pre></arr.length;>

사용자 정의 방법 사용

다음 예에서는 이름이 지정된 메서드를 정의했습니다. 정렬 배열() 배열을 자연 순서로 정렬하는 논리가 포함되어 있습니다.

SortArrayExample3.java 

 public class SortArrayExample3 { public static void main(String[] args) { int i; //initializing an array int array[] = {12, 45, 1, -1, 0, 4, 56, 23, 89, -21, 56, 27}; System.out.print(&apos;Array elements before sorting: 
&apos;); for(i = 0; i <array.length; i++) system.out.println(array[i]); invoking user defined method sortarray(array, array.length); system.out.print(\'array elements after sorting: 
\'); accessing of the sorted array for(i="0;" i <array.length; { } to sort an in ascending order private static void sortarray(int array[], int n) for (int <n; j="i;" a="array[i];" while ((j> 0) &amp;&amp; (array[j-1] &gt; a)) //returns true when both conditions are true { array[j] = array[j-1]; j--; } array[j] = a; } } } </array.length;>

산출: 

 Array elements before sorting: 12 45 1 -1 0 4 56 23 89 -21 56 27 Array elements after sorting: -21 -1 0 1 4 12 23 27 45 56 56 89

내림차순으로 배열 정렬

그만큼 내림차순 요소를 가장 높은 순서에서 가장 낮은 순서로 정렬합니다. 다음과 같은 방법으로 정렬을 수행할 수 있습니다.

  • 사용하여 역순으로() 방법
  • 방법을 사용하지 않고
    • 사용하여 ~을 위한 고리
    • 사용하여 사용자 정의 방법

reverseOrder() 메서드 사용

자바 컬렉션 수업 제공합니다 역순으로() 배열을 역사전순으로 정렬하는 방법입니다. 이는 정적 메서드이므로 클래스 이름을 사용하여 직접 호출할 수 있습니다. 어떤 매개변수도 구문 분석하지 않습니다. 그것은 비교기 이는 자연 순서(오름차순)의 반대 순서를 적용합니다.

이는 배열이 sort() 메서드를 사용하여 오름차순으로 요소를 정렬한 후 reverseOrder() 메서드가 자연 순서를 반대로 하여 내림차순으로 정렬된 배열을 얻는다는 의미입니다.

통사론: 

 public static Comparator reverseOrder()

a[]는 내림차순으로 정렬할 배열이라고 가정합니다. 다음과 같은 방법으로 reverseOrder() 메서드를 사용합니다.

 Arrays.sort(a, Collections.reverseOrder());

내림차순으로 배열을 정렬해 보겠습니다.

다음 프로그램에서 주목해야 할 점은 배열을 다음과 같이 정의했다는 것입니다. 정수 . reverseOrder() 메소드는 기본 데이터 유형에 대해 작동하지 않기 때문입니다.

SortArrayExample4.java 

 import java.util.Arrays; import java.util.Collections; public class SortArrayExample4 { public static void main(String[] args) { Integer [] array = {23, -9, 78, 102, 4, 0, -1, 11, 6, 110, 205}; // sorts array[] in descending order Arrays.sort(array, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(array)); } }

산출: 

 Array elements in descending order: [205, 110, 102, 78, 23, 11, 6, 4, 0, -1, -9]

배열 요소를 알파벳 순서로 정렬하는 다른 프로그램을 살펴보겠습니다.

SortArrayExample5.java 

 import java.util.Arrays; import java.util.Collections; public class SortArrayExample5 { public static void main(String[] args) { String [] strarray = {&apos;Mango&apos;, &apos;Apple&apos;, &apos;Grapes&apos;, &apos;Papaya&apos;, &apos;Pineapple&apos;, &apos;Banana&apos;, &apos;Orange&apos;}; // sorts array[] in descending order Arrays.sort(strarray, Collections.reverseOrder()); System.out.println(&apos;Array elements in descending order: &apos; +Arrays.toString(strarray)); } }

산출: 

 Array elements in descending order: [Papaya, Pineapple, Orange, Mango, Grapes, Banana, Apple]

방법을 사용하지 않고

for 루프 사용

다음 예제에서는 정수 배열을 초기화하고 내림차순으로 정렬을 수행했습니다.

SortArrayExample6.java 

 public class SortArrayExample6 { public static void main(String[] args) { int temp; //initializing an array int a[]={12,5,56,-2,32,2,-26,9,43,94,-78}; for (int i = 0; i <a.length; i++) { for (int j="i" + 1; < a.length; j++) if (a[i] a[j]) temp="a[i];" a[i]="a[j];" a[j]="temp;" } system.out.println(\'array elements in descending order:\'); accessing element of the array i="0;" - system.out.println(a[i]); pre> <p> <strong>Output:</strong> </p> <pre> Array elements in descending order: 94 56 43 32 12 9 5 2 -2 -26 -78 </pre> <h3>Using the User Defined Method</h3> <p> <strong>SortArrayExample7.java</strong> </p> <pre> import java.util.Scanner; public class SortArrayExample7 { public static void main(String[] args) { int n, temp; Scanner s = new Scanner(System.in); System.out.print(&apos;Enter the number of elements: &apos;); n = s.nextInt(); int a[] = new int[n]; System.out.println(&apos;Enter the elements of the array: &apos;); for (int i = 0; i <n; i++) { a[i]="s.nextInt();" } for (int i="0;" < n; j="i" + 1; j++) if (a[i] a[j]) temp="a[i];" a[j]="temp;" system.out.println(\'array elements in descending order:\'); n - system.out.println(a[i]); system.out.print(a[n 1]); pre> <p> <strong>Output:</strong> </p> <pre> Enter the number of elements: 7 Enter the elements of the array: 12 5 56 -2 32 2 -26 Array elements in descending order: 56 32 12 5 2 -2 -26 </pre> <h2>How to Sort Subarray</h2> <p>An array derived from the array is known as <strong>subarray</strong> . Suppose, <strong>a[]</strong> is an array having the elements [12, 90, 34, 2, 45, 3, 22, 18, 5, 78] and we want to sort array elements from 34 to 18. It will sort the subarray <strong>[34, 2, 45, 3, 22, 18]</strong> and keep the other elements as it is.</p> <p>To sort the subarray, the Arrays class provides the static method named <strong>sort()</strong> . It sorts the specified range of the array into ascending order. We can also sort the array of type <strong>long, double, float, char, byte,</strong> etc.</p> <p> <strong>Syntax:</strong> </p> <pre> public static void sort(int[] a, int fromIndex, int toIndex) </pre> <p>The method parses the following three parameters:</p> <ul> <tr><td>a:</td> An array to be sort. </tr><tr><td>fromIndex:</td> The index of the first element of the subarray. It participates in the sorting. </tr><tr><td>toIndex:</td> The index of the last element of the subarray. It does not participate in the sorting. </tr></ul> <p>If formIndex is equal to the toIndex, the range to be sorted is empty. It throws IllegalArgumentException if <strong>fomIndex is greater than toIndex</strong> . It also throws ArrayIndexOutOfBoundsException if <strong>fromIndex a.length</strong> .</p> <p>Let&apos;s sort a subarray through a Java program.</p> <p> <strong>SortSubarrayExample.java</strong> </p> <pre> import java.util.Arrays; public class SortSubarrayExample { public static void main(String[] args) { //defining an array int[] a = {12, 90, 34, 2, 45, 3, 22, 18, 5, 78}; // sorts subarray form index 2 to 7 Arrays.sort(a, 2, 7); //prints array using the for loop for (int i = 0; i <a.length; i++) { system.out.println(a[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Sorted Subarray: 12 90 2 3 22 34 45 18 5 78 </pre> <hr></a.length;></pre></n;></pre></a.length;>

사용자 정의 방법 사용

SortArrayExample7.java 

 import java.util.Scanner; public class SortArrayExample7 { public static void main(String[] args) { int n, temp; Scanner s = new Scanner(System.in); System.out.print(&apos;Enter the number of elements: &apos;); n = s.nextInt(); int a[] = new int[n]; System.out.println(&apos;Enter the elements of the array: &apos;); for (int i = 0; i <n; i++) { a[i]="s.nextInt();" } for (int i="0;" < n; j="i" + 1; j++) if (a[i] a[j]) temp="a[i];" a[j]="temp;" system.out.println(\'array elements in descending order:\'); n - system.out.println(a[i]); system.out.print(a[n 1]); pre> <p> <strong>Output:</strong> </p> <pre> Enter the number of elements: 7 Enter the elements of the array: 12 5 56 -2 32 2 -26 Array elements in descending order: 56 32 12 5 2 -2 -26 </pre> <h2>How to Sort Subarray</h2> <p>An array derived from the array is known as <strong>subarray</strong> . Suppose, <strong>a[]</strong> is an array having the elements [12, 90, 34, 2, 45, 3, 22, 18, 5, 78] and we want to sort array elements from 34 to 18. It will sort the subarray <strong>[34, 2, 45, 3, 22, 18]</strong> and keep the other elements as it is.</p> <p>To sort the subarray, the Arrays class provides the static method named <strong>sort()</strong> . It sorts the specified range of the array into ascending order. We can also sort the array of type <strong>long, double, float, char, byte,</strong> etc.</p> <p> <strong>Syntax:</strong> </p> <pre> public static void sort(int[] a, int fromIndex, int toIndex) </pre> <p>The method parses the following three parameters:</p> <ul> <tr><td>a:</td> An array to be sort. </tr><tr><td>fromIndex:</td> The index of the first element of the subarray. It participates in the sorting. </tr><tr><td>toIndex:</td> The index of the last element of the subarray. It does not participate in the sorting. </tr></ul> <p>If formIndex is equal to the toIndex, the range to be sorted is empty. It throws IllegalArgumentException if <strong>fomIndex is greater than toIndex</strong> . It also throws ArrayIndexOutOfBoundsException if <strong>fromIndex a.length</strong> .</p> <p>Let&apos;s sort a subarray through a Java program.</p> <p> <strong>SortSubarrayExample.java</strong> </p> <pre> import java.util.Arrays; public class SortSubarrayExample { public static void main(String[] args) { //defining an array int[] a = {12, 90, 34, 2, 45, 3, 22, 18, 5, 78}; // sorts subarray form index 2 to 7 Arrays.sort(a, 2, 7); //prints array using the for loop for (int i = 0; i <a.length; i++) { system.out.println(a[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Sorted Subarray: 12 90 2 3 22 34 45 18 5 78 </pre> <hr></a.length;></pre></n;>

하위 배열을 정렬하는 방법

배열에서 파생된 배열은 다음과 같이 알려져 있습니다. 하위 배열 . 가정하다, ㅏ[] 는 [12, 90, 34, 2, 45, 3, 22, 18, 5, 78] 요소를 갖는 배열이고 우리는 배열 요소를 34에서 18까지 정렬하려고 합니다. 하위 배열을 정렬합니다. [34, 2, 45, 3, 22, 18] 다른 요소는 그대로 유지합니다.

b+ 트리

하위 배열을 정렬하기 위해 Arrays 클래스는 다음과 같은 정적 메서드를 제공합니다. 종류() . 배열의 지정된 범위를 오름차순으로 정렬합니다. 유형의 배열을 정렬할 수도 있습니다. long, double, float, char, 바이트, 등.

통사론: 

 public static void sort(int[] a, int fromIndex, int toIndex)

이 메서드는 다음 세 가지 매개변수를 구문 분석합니다.

    ㅏ:정렬할 배열입니다.fromIndex:하위 배열의 첫 번째 요소에 대한 인덱스입니다. 정렬에 참여합니다.인덱스:하위 배열의 마지막 요소에 대한 인덱스입니다. 정렬에는 참여하지 않습니다.

formIndex가 toIndex와 같으면 정렬할 범위가 비어 있습니다. 다음과 같은 경우 IllegalArgumentException이 발생합니다. fomIndex가 toIndex보다 큽니다. . 또한 다음과 같은 경우 ArrayIndexOutOfBoundsException이 발생합니다. fromIndex a.길이 .

Java 프로그램을 통해 하위 배열을 정렬해 보겠습니다.

SortSubarrayExample.java 

 import java.util.Arrays; public class SortSubarrayExample { public static void main(String[] args) { //defining an array int[] a = {12, 90, 34, 2, 45, 3, 22, 18, 5, 78}; // sorts subarray form index 2 to 7 Arrays.sort(a, 2, 7); //prints array using the for loop for (int i = 0; i <a.length; i++) { system.out.println(a[i]); } < pre> <p> <strong>Output:</strong> </p> <pre> Sorted Subarray: 12 90 2 3 22 34 45 18 5 78 </pre> <hr></a.length;>