Common ways to manipulate arrays in Java

1. Declaring an array

1 New String[5];   2 string[] arr2 = {"a", "b", "c", "d", "e"};   3 New string[]{"a", "b", "c", "d", "e"};  

2. Output an array

 1  int  [] arr = {1, 2, 3, 4, 5 };  2  String arrstring = arrays.tostring (arr  );  3  4  //  Direct output, for memory address   5  system.out.println (arr);   6  //  7    System.out.println (arrstring);   9  //  

3. Check if an array contains a value

1 string[] arr= {"a", "b", "c", "d", "e" };   2 Boolean b = arrays.aslist (arr). contains ("a");   3 System.out.println (b);   4 // true  

4. Connect two arrays

1 // using the Apache Commons Lang Library 2 3 int [] arr1 = {1, 2, 3, 4, 5 };   4 int [] arr2= {6, 7, 8, 9, ten };   5 int

 //system.arraycopy () 
 1  static   string[] concat (string[] a, string[] b) { 2  string[] C = new  string[a.length + B.leng th];  3  system.arraycopy (a, 0, c, 0, a.length);  4  system.arraycopy (b, 0 5  return   c;  6 } 

 1  //  2  3  public  static  int  [] concat ( Span style= "color: #0000ff;" >int  [] first, int  [] second) { Span style= "color: #008080;" >4  int  [] result = arrays.copyof (first, first.length + second.length);  5  system.arraycopy (second, 0 6  return   result;  7 } 

5. Reverse output an array

1 // Apache Commons Lang Library 2 3 int [] arr= {1, 2, 3, 4, 5 };   4 arrayutils.reverse (intarray);   5 System.out.println (arrays.tostring (intarray));   6 // [5, 4, 3, 2, 1]  

1 int[] arr = {1, 2, 3, 4, 5 };2 int[] Revarr =New int[arr.length];3  for(inti = 0; I < arr.length; i++){4revarr[i] = arr[arr.length-i-1];5 }6 System.out.println (arrays.tostring (revarr));7 8 //[5, 4, 3, 2, 1]

6. Move the elements in the divisor group

1 // Apache Common Lang   2 3 int [] arr= {1, 2, 3, 4, 5 };   4 int [] removed = arrayutils.removeelement (intarray, 3); // Create a new array   5 System.out.println (arrays.tostring (REMOVED))

Common ways to manipulate arrays in Java