Question

I am trying to replace all characters except last 4 in a String with * s.
In objective-c there is a method in NSString class replaceStringWithCharactersInRange: withString: where I would give it range (0,[string length]-4) ) with string @"*". This is what it does: 123456789ABCD is modified to *ABCD while I am looking to make ********ABCD. I understand that it replaced range I specified with string object. How to accomplish this ?

Answer 1

NSError *error;

NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"\d" options:NSRegularExpressionCaseInsensitive error:&error];

NSString *newString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:@"*"];

Answer 2

This looks like a simple problem... get the first part string and return it with the last four characters appended to it.
Here is a function that returns the needed string :

-(NSString *)neededStringWithString:(NSString *)aString {
    // if the string has less than or 4 characters, return nil
    if([aString length] <= 4) {
        return nil;
    }
    NSUInteger countOfCharToReplace = [aString length] - 4;
    NSString *firstPart = @"*";
    while(--countOfCharToReplace) {
        firstPart = [firstPart stringByAppendingString:@"*"];
    }
    // range for the last four
    NSRange lastFourRange = NSMakeRange([aString length] - 4, 4);
    // return the combined string
    return [firstPart stringByAppendingString:
            [aString substringWithRange:lastFourRange]];
}

Answer 3

可可中最不可靠的部分正在制造重复的恒星,没有某种宽松。。允许你重复你喜欢的一段时期,这样一来,你就能够在此简单地解决问题:

NSInteger starUpTo = [string length] - 4;
if (starUpTo > 0) {
    NSString *stars = [@"" stringByPaddingToLength:starUpTo withString:@"*" startingAtIndex:0];
    return [string stringByReplacingCharactersInRange:NSMakeRange(0, starUpTo) withString:stars];
} else {
    return string;
}

Answer 4

我不敢肯定为什么接受所接受的答复,因为只有一切,最后4个只是一位数。这里简单:

NSMutableString * str1 = [[NSMutableString alloc]initWithString:@"1234567890ABCD"];
NSRange r = NSMakeRange(0, [str1 length] - 4);
[str1 replaceCharactersInRange:r withString:[[NSString string] stringByPaddingToLength:r.length withString:@"*" startingAtIndex:0]];
NSLog(@"%@",str1);

Answer 5

您可使用<代码>[String substring ToIndex:[String length]-4],以获得座右的第一部分,然后将[String length]-4 *与第二部分合并。也许,它们更容易做到这一点。

Answer 6

NSMutableString * str1 = [[NSMutableString alloc]initWithString:@"1234567890ABCD"];
[str1 replaceCharactersInRange:NSMakeRange(0, [str1 length] - 4) withString:@"*"];
NSLog(@"%@",str1);

它的工作

Answer 7

The regexp don t work on Ri7, but may this helps:

- (NSString *)encryptString:(NSString *)pass {

    NSMutableString *secret = [NSMutableString new];

    for (int i=0; i<[pass length]; i++) {
        [secret appendString:@"*"];
    }

    return secret;
}

在你的情况下,你应停止更换最后4个特性。做比特工,但获得工作

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