java System.arraycopy()

package study.stage2;

import java.util.Arrays;

/**
 * Created by Sandy.Liu on 2017/7/19.
 */
public class ArrayTest {
    public static void main(String[] args) throws Exception{
        int array[] = {3,4,2,24,6,-23,-4,-56};
        System.out.println(array.length);//8
        printArray(array);//{3,4,2,24,6,-23,-4,-56}
        array = insertElement(array,1,5);
        printArray(array);//{3,4,2,24,6,1,-23,-4,-56}
        Arrays.sort(array);
        printArray(array);//{-56,-23,-4,1,2,3,4,6,24}
        int index = Arrays.binarySearch(array,4);
        System.out.println(index);
    }
    public static void printArray(int array[]){
        for(int i=0;i<array.length;i++){
            System.out.print(array[i]+" ");
        }
        System.out.println();
    }

    public static int[] insertElement(int original[], int element, int index){
        int length = original.length;
        if(index<0){
            System.out.println("out of range");
        }
        else if(index>original.length){
            System.out.println("out of range");
        }
        int destination[] = new int[length+1];
        //arrayCopy(originalArray,index, targetArray,index1,count) 把orginal里的从index位开始的值copy到targetArray里从index1开始的位置，
        // ，copy的位数是count
        System.arraycopy(original,0,destination,0,index);
        destination[index]=element;
        System.arraycopy(original,index,destination,index+1,length-index);
        return destination;

    }
}