一.去除首尾的空格

    /** 1.去除首尾的空格*/
    NSString *strMsg=@"  简书作者:CoderZb   ";
    NSString *strResult = [strMsg stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    NSLog(@"去除空格前:%@",strMsg);
    NSLog(@"去除空格后:%@",strResult);

去除首尾空格.png

二.去除连续的字符集

    /** 2.去除指定的字符集*/    
    NSString *strMsg2=@"简书作者:CoderZb";
    id cs= [NSCharacterSet characterSetWithCharactersInString:@"简书作者:"];
    NSString *strResult2=[strMsg2 stringByTrimmingCharactersInSet:cs];
    NSLog(@"去除之后的结果:%@",strResult2);

去除连续的字符集.png

三.去除任意的字符集(连续、非连续都可)

    /** 3.删除任意的字符集*/
    NSString *strMsg=@"简书作者:CoderZb";
    NSCharacterSet *cs= [NSCharacterSet characterSetWithCharactersInString:@"简者Cdb"];
    NSMutableString *theString=[NSMutableString stringWithString:strMsg];// 将strMsg变为可变字符串
    NSString *strResult= [self clearnIllegitCharacters:theString andCharacterSet:cs];
    NSLog(@"删除任意的字符集的结果:%@",strResult);

// 清除敏感词语
- (NSString *)clearnIllegitCharacters:(NSMutableString *)originString andCharacterSet:(NSCharacterSet *)cs{

    NSString *strResult=nil;
    NSRange range2;
    do {
        range2=[originString rangeOfCharacterFromSet:cs options:NSLiteralSearch];
        if (range2.location!=NSNotFound) {// range2.location不为NSNotFound,就执行{}

            // [originString deleteCharactersInRange:range2];// 删除range2代表的字符集
            [originString replaceCharactersInRange:range2 withString:@"*"];// 用星号替换掉range2代表的字符集
        }
    } while (range2.location!=NSNotFound);// range2.location不为NSNotFound,就执行do{},直至等于NSNotFound,就不再执行do{}

    // 可变字符串变为不可变
    strResult=[[NSString alloc] initWithString:originString];

    return strResult;


}

[originString replaceCharactersInRange:range2 withString:@"*"];// 用星号替换掉range2代表的字符集

用*替换掉字符集.png

[originString deleteCharactersInRange:range2];// 删除range2代表的字符集

删除任意的字符集.png

四.字符串分割(常用)方式1:

    #define kAlphaNum @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

    NSString *str = @"简书作者:Coder#Z@b";
    NSCharacterSet *cs;
    // invertedSet方法是取反字符。所以cs的值为:除了kAlphaNum里的字符,其余的任何字符都是cs
    cs = [[NSCharacterSet characterSetWithCharactersInString:kAlphaNum] invertedSet];
    // 将str按cs分割成数组(既然能分割,说明cs是str的子集,并且cs中的字符不会在str中出现,相当于str中删除了这些字符),最后将数组按照@""分割成字符串
    NSString *filtered = [[str componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
    NSLog(@"字符串->数组->字符串   %@", filtered);

字符串->数组->字符串.png

四.字符串分割(常用)方式2:

    NSString *str = @"简书作者:Coder#Z@b";
    //按@"#简书@作者:"将str分离成数组,然后将数组按@"-"拼接成字符串
    NSString *filtered = [[str componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"#简书@作者:"]] componentsJoinedByString:@"-"]; 
    NSLog(@"%@", filtered);

NSCharacterSet去除字符串中的空格、删除指定\任意字符集