字符串的插入、删除、查找并删除、重新赋值、替换

#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);

    }

    return 0;

}