字符串拼接的三种方式

NSString* string; // 结果字符串

NSString* string1, string2; //已存在的字符串，需要将string1和string2连接起来

//方法1.

string = [NSString initWithFormat:@"%@,%@", string1, string2 ];

//方法2.

string = [string1 stringByAppendingString:string2];

//方法3 .

string = [string stringByAppendingFormat:@"%@,%@",string1, string2];