OC字符串方法总结

来源：互联网发布：北风网php 百度云编辑：程序博客网时间：2024/04/30 13:30

/--------操作字符串--NSString(静态字符串)---------------------
    NSString *Beijing= @"北京欢迎您";        //字符串的声明
    NSString *log=@"北京欢迎您a"; //[NSString stringWithFormat:@"I am '%@'",Beijing];     //字符串格式化
    NSString *zhui = [Beijing stringByAppendingString:@"哈哈哈"];        //字符串追加
    bool b=[Beijing isEqualToString:log];                               //字符串比较
    NSString *hh = @"http://www.sina.com.cn";
    if([hh hasPrefix:@"http"]){                                          //查找以http开头的字符串
        NSLog(@"含有http");
    }else{
        NSLog(@"没有http");
    }
    NSString *ss = @"123";
    int a = [ss intValue]+13;                                   //字符串转int型
    double dd = [ss doubleValue]+33.3;                          //字符串转double型
    NSLog(@"%g",dd);
//字符串转数组
    NSString *zifuchuan =@"one,two,three,four";
    NSLog(@"string:%@",zifuchuan);
    NSArray *array = [zifuchuan componentsSeparatedByString:@","];
//    NSLog(@"array:%@",array);                             //输出整个数组中所有元素
    NSString *value = [array objectAtIndex:0];          //取出第0个元素
    NSLog(@"value:%@",value);
//数组转字符串
    NSString * zifuchuan2 = [array componentsJoinedByString:@","];
    NSLog(@"zifuchuan2:%@",zifuchuan2);

//-substringToIndex: 从字符串的开头一直截取到指定的位置，但不包括该位置的字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
NSLog(@"string2:%@",string2);

//-substringFromIndex: 以指定位置开始（包括指定位置的字符），并包括之后的全部字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringFromIndex:3];
NSLog(@"string2:%@",string2);

//-substringWithRange: //按照所给出的位置，长度，任意地从字符串中截取子串
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
NSLog(@"string2:%@",string2);

//--------操作动态字符串--NSMutableString----------------------------------------------------
    NSMutableString *mstr = [[NSMutableString alloc] init];
    NSString *str1 = @"This is a example.";
    //创建可变字符串
    mstr = [NSMutableString stringWithString:str1];
    //插入字符
    [mstr insertString:@"very easy " atIndex:10];
    //删除一些字符
    [mstr deleteCharactersInRange:NSMakeRange(10,5)];
    //查找并删除
    NSRange substr = [mstr rangeOfString:@"example"];             //字符串查找,可以判断字符串中是否有
    if (substr.location != NSNotFound) {
        [mstr deleteCharactersInRange:substr];
    }
    //重新设置字符串
    [mstr setString:@"This is string AAA"];
    //替换字符串
    [mstr replaceCharactersInRange:NSMakeRange(15, 2) withString:@"BBB"];   //从第15个字符串处替换掉后2个字符串

    //查找第一个并替换
    NSString *search = @"This is";
    NSString *replace = @"An example of";
    substr = [mstr rangeOfString:search];
    if (substr.location != NSNotFound) {
        [mstr replaceCharactersInRange:substr withString:replace];      //把第1个遇到的substr替换为replace
        NSLog(@"%@",mstr);
    }

    //查找全部匹配的，并替换
    search = @"a";
    replace = @"X";
    substr = [mstr rangeOfString:search];
    while (substr.location != NSNotFound) {
        [mstr replaceCharactersInRange:substr withString:replace];
        substr = [mstr rangeOfString:search];
    }
    NSLog(@"%@",mstr);

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