replace replace_if

#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>

class myprint
{
public:
	void operator()(int val) {
		cout << val << endl;
	}

};


void test() {
	vector<int> v;
	v.push_back(20);
	v.push_back(30);
	v.push_back(40);
	v.push_back(50);

	for_each(v.begin(), v.end(), myprint());
	replace(v.begin(), v.end(),20,3000);
	for_each(v.begin(), v.end(), myprint());
}

int main() {
	test();
}

3000,30,40,50

#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>

class myprint
{
public:
	void operator()(int val) {
		cout << val << endl;
	}

};

//谓词, 返回bool 类型
class great50
{
public:
	bool operator()(int val)
	{
		return val > 30;
	}

};



void test() {
	vector<int> v;
	v.push_back(60);
	v.push_back(60);
	v.push_back(60);
	v.push_back(60);

	for_each(v.begin(), v.end(), myprint());
	replace_if(v.begin(), v.end(), great50(),3000);
	for_each(v.begin(), v.end(), myprint());
}

int main() {
	test();
}

60 60 60 60
3000 3000 3000 3000