Don't pass by value. Because the formal parameter copies the value of the actual parameter, after the function is called, the space is released, and the exchange result cannot be transmitted. The parameter should be a reference type.
1. The swap function is defined as a public type
public class Test_Swap {
//public函数
public void swap(int[] brr,int index1,int index2){
int tmp=brr[index1];
brr[index1]=brr[index2];
brr[index2]=tmp;
}
public static void main(String[] args) {
int[] arr= {
10,20};
//依赖于对象，需要通过 对象. 来调用
Test_Swap test=new Test_Swap() ;
test.swap(arr,0,1);
System.out.println(arr[0]+" "+arr[1]);
}
}
2. The swap function is defined as a public static type
public class Test_Swap {
//定义为静态方法
public static void swap(int[] brr,int index1,int index2){
int tmp=brr[index1];
brr[index1]=brr[index2];
brr[index2]=tmp;
}
public static void main(String[] args) {
int[] arr= {
10,20};
//两种调用方法
Test_Swap.swap(arr,0,1);
//swap(arr,0,1);
System.out.println(arr[0]+" "+arr[1]);
}
}