6.2 函数（2）

r囧r小猫 2022-05-20 08:30 143阅读 0赞

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数组形参的改变会影响实参的改变。Swap（a，b）改变的只是形参的值，是实参拷贝过去的值，并不影响实参的改变。

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#include<iostream>
    using namespace std;
    int a1[4] = {4, 5, 6, 9};
    int a2[] = {3, 18, 56, 40, 78};
    int FindMax(int a[], int length)
    {
    	int maxn;
    	for(int i = 0; i < length; ++i)
    	{
    		if(a[i] > maxn)
    			maxn = a[i];
    	}
    	return maxn;
    }
    int main()
    {
    	cout << FindMax(a1,sizeof(a1)/sizeof(int)) << endl;//9 length = sizeof(a1)/sizeof(int)=4
    	cout << FindMax(a2,sizeof(a2)/sizeof(int)) << endl;//78
    	return 0;
    }

![70 7][]

#include<iostream>
    using namespace std;
    int a1[4] = {4, 15, 6, 9};
    void SetToZero(int a[], int length)//没有返回值 
    {
    	for(int i = 0; i < length; ++i)
    	{
    		a[i] = 0;
    	}
    }
    int main()
    {
    	SetToZero(a1, 4); 
    	for(int i = 0; i < 4; ++i)// 数组形参的值会影响实参，所以a1数组的所有元素值都为0 
    	{
    		cout << a1[i] << " ";
    	} 
    	return 0;
    }

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[70 8]: /images/20220520/a4138168d40743a6910005b9af26fb38.png