Arraysクラス

2892 ワード

しゅつりょく

  • toString():最初の配列のすべての要素を文字列
  • として簡単に出力できます.
  • deepToString():2 D以上のアレイで使用可能
    import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int[] arr = {0,1,2,3,4};
            int[][] arr2D = {{0,1},{0,1}};
            System.out.println(Arrays.toString(arr));
            System.out.println(Arrays.deepToString(arr2D));
        }
    }
    출력 : [0, 1, 2, 3, 4]
    [[0, 1], [0, 1]]

    比較

  • equals():2つのプライマリ配列に格納されているすべての要素を比較し、同じtrueを導出し、false
  • を返す.
    import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int [] arr = {1,2,3,4};
            int [] arr2 = {1,2,3,4};
            System.out.println(Arrays.equals(arr,arr2));
        }
    }
    출력 : true
  • deepEquals():2 D以上のアレイで使用できます.
  • import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int [][] arr = {{1,2,3,4},{3,4,6,7}};
            int [][] arr2 = {{1,2,3,4},{3,4,6,7}};
            System.out.println(Arrays.equals(arr,arr2));
            System.out.println(Arrays.deepEquals(arr,arr2));
        }
    }
    출력 : false
    true

    ふくしゃ

  • copyOf():アレイ全体をコピーして新しいアレイを作成します.
  • import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int [] arr = {1,2,3,4};
            int [] arr1 = Arrays.copyOf(arr,1);
            int [] arr2 = Arrays.copyOf(arr,2);
            int [] arr_clone = Arrays.copyOf(arr, arr.length);
            System.out.println(Arrays.toString(arr)); 
            System.out.println(Arrays.toString(arr1));
            System.out.println(Arrays.toString(arr2));
            System.out.println(Arrays.toString(arr_clone));
        }
    }
    출력 : [1, 2, 3, 4]
    [1]
    [1, 2]
    [1, 2, 3, 4]
  • copyOfRange():アレイの一部をコピーして新しいアレイを作成します.
  • import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int [] arr = {1,2,3,4};
            int [] arr1 = Arrays.copyOfRange(arr,0,3);
            int [] arr2 = Arrays.copyOfRange(arr,1,4);
            int [] arr_clone = Arrays.copyOfRange(arr, 0,arr.length);
            System.out.println(Arrays.toString(arr));
            System.out.println(Arrays.toString(arr1));
            System.out.println(Arrays.toString(arr2));
            System.out.println(Arrays.toString(arr_clone));
        }
    }
    출력:[1, 2, 3, 4]
    [1, 2, 3]
    [2, 3, 4]
    [1, 2, 3, 4]

    ツールバーの

  • sort():配列
  • import java.util.Arrays;
    public class Main1 {
        public static void main(String[] args) {
            int [] arr = {7,8,32,2,1,0};
            System.out.println(Arrays.toString(arr));
            Arrays.sort(arr);
            System.out.println(Arrays.toString(arr));
        }
    }
    출력 : [7, 8, 32, 2, 1, 0]
    [0, 1, 2, 7, 8, 32]