可变字符串 插入 删除 重赋值 替换 前后缀 长度

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {

    @autoreleasepool {      

        //nsstring父类   NSMutableString可变字符串子类        

NSMutableString *mustr=[[NSMutableString alloc]init];

NSMutableString *mustr1=[NSMutableString stringWithFormat:@"Hello"];

  //将不可变的字符串放置到可变字符串内

      NSString *str=@"welcome to oc"; 

        mustr=[NSMutableString stringWithString:str];

  //插入

        [mustr insertString:@" students " atIndex:7];

        [mustr appendString:@" teacher"];

        [mustr appendFormat:@"第二遍插入:%@",str];

  //删除

        [mustr deleteCharactersInRange:NSMakeRange(8, 10)];

  //查找并删除        

        NSRange rang=[mustr rangeOfString:@"第二遍插入:welcome to oc"];

        if (rang.location!=NSNotFound) {

            [mustr deleteCharactersInRange:rang];

        }

     //重新赋值

        [mustr setString:str];

      //替换

        NSRange rang1=[mustr rangeOfString:@"oc"];

        [mustr replaceCharactersInRange:rang1 withString:@"IOS"];

        NSLog(@"%@",mustr);

  //判断字符串是否有此前缀

        NSString *str=@"IOS8-赵玉鑫.jpg";

      BOOL result = [str hasPrefix:@"IOS"];

        NSLog(@"%d",result);

       //判断字符串是否有此后缀

      BOOL resultsu = [str hasSuffix:@".jpg"];

        NSLog(@"%d",resultsu);

 长度

//1.定义字符串对象

        NSString *str=[NSString stringWithString:@"zi fu chuan"];

        //2.计算字符串长度

        NSUInteger len = [str length];

        //3.输出字符串长度

        NSLog(@"zi fu chuan的长度是%ld",len);

    }

    return 0;

}