編寫一程序，將兩個字符串連接起來的3種方法

1.用字符數組和自己書寫的函數實現

自己寫一個具有strcat函數功能的函數

實現代碼如下：

#include<iostream>
using namespace std;
int main(){
	char a[100],b[50];
	void Strcat(char a[],char b[]);
	cout<<"please input first string:"<<endl;
	cin>>a;
	cout<<"please input second string:"<<endl;
	cin>>b;
	Strcat(a,b);
	cout<<"The new string: "<<a;
	cout<<endl;
	return 0;	
}
void Strcat(char a[],char b[]){
	int i,j;
	for(i=0;a[i]!='\0';i++);
	cout<<"Length of first string:"<<i<<endl;
	for(j=0;b[j]!='\0';j++,i++){
		a[i]=b[j];
	}
	cout<<"Length of second string:"<<j<<endl;
}

2.用標准庫中的strcat函數

使用strlen()函數求數組的大小，strcat()函數用來連接字符串

實現代碼如下：

#include<iostream>
#include<string>
using namespace std;
int main(){
	char a[100],b[50];
	cout<<"please input first string:"<<endl;
	cin>>a;
	cout<<"please input second string:"<<endl;
	cin>>b;
	cout<<"Length of first string :"<<strlen(a)<<endl;
	cout<<"Length of first string :"<<strlen(b)<<endl;	
	cout<<"The new string: "<<strcat(a,b);
	cout<<endl;
	return 0;	
}

3.用string方法定義字符串變量

#include<iostream>
#include<string>
using namespace std;
int main(){
	string a,b;
	cout<<"please input first string:"<<endl;
	cin>>a;
	cout<<"please input second string:"<<endl;
	cin>>b;
	cout<<"New string :"<<(a+b)<<endl;
	return 0;	
}