Java中与数组相关的方法

1. Arrays.sort() ; Arrays.toString()

import java.util.Arrays;

public class Test11 {
	public static void main(String[] args) {
		int[] arr=new int[] {1,0,9,8,4,5,6};
		Arrays.sort(arr);
		System.out.println(Arrays.toString(arr));
	}
}

2. Arrays.copyOf()

import java.util.Arrays;

public class Test11 {
	public static void main(String[] args) {
		int[] ic = { 0, 1, 2, 3, 4 };
		int[] id = Arrays.copyOf(ic, ic.length);// 若第二个参数大于ic的元素个数，则相应的元素初值为0
		System.out.println(Arrays.toString(id));
	}
}

3. System.arraycopy(from , fromIndex , to , toIndex , count )

import java.util.Arrays;

public class Test11 {
	public static void main(String[] args) {
		int[] ia = { 0, 1, 2, 3, 4 };
		int[] ib = { 100, 101, 102, 103, 104, 105 };
		System.arraycopy(ib,4,ia,2,2);//不是插入，是替换，不能越界复制
		System.out.println(Arrays.toString(ia));
	}
}

4. Arrays.deepToString()

import java.util.Arrays;

public class Test11 {
	public static void main(String[] args) {
	//交换二维数组两行
		int [ ][ ] a={{1,2},{2,3},{3,4,5}}; 
		 int [] temp=a[0]; 
		 a[0]=a[1]; 
		 a[1]=temp;       
		 System.out.println(Arrays.deepToString(a));
	}
}