String replacement in Objective-C

Question

How to replace a character is a string in Objective-C?

epatel · Accepted Answer · 2009-03-20T22:45:55.403

806

You could use the method

- (NSString *)stringByReplacingOccurrencesOfString:(NSString *)target 
                                        withString:(NSString *)replacement

...to get a new string with a substring replaced (See NSString documentation for others)

Example use

NSString *str = @"This is a string";

str = [str stringByReplacingOccurrencesOfString:@"string"
                                     withString:@"duck"];

edited Mar 20 '09 at 22:45

answered Mar 20 '09 at 22:39

epatel

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I thought the point of having NSString and an NSMutableString subclass was because an instance of NSString is *unchangeable*. While--like any sane person, I'd rather have ducks than strings any day--the fact that you just overwrote the contents of `str` just blew my mind. – ele Apr 01 '13 at 21:42
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But I guess the adress of `str` changed in the process – Colas Apr 02 '13 at 18:49
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it doesn't change. str now contains a whole new string. stringByReplacingOccurencesOfString does NOT mutate the string. It simply return a new string. – Septiadi Agus Jun 28 '13 at 08:56

score 22 · Answer 2 · answered Mar 20 '09 at 22:39

22

NSString objects are immutable (they can't be changed), but there is a mutable subclass, NSMutableString, that gives you several methods for replacing characters within a string. It's probably your best bet.

answered Mar 20 '09 at 22:39

mipadi

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score 10 · Answer 3 · edited Sep 18 '15 at 14:47

10

If you want multiple string replacement:

NSString *s = @"foo/bar:baz.foo";
NSCharacterSet *doNotWant = [NSCharacterSet characterSetWithCharactersInString:@"/:."];
s = [[s componentsSeparatedByCharactersInSet: doNotWant] componentsJoinedByString: @""];
NSLog(@"%@", s); // => foobarbazfoo

edited Sep 18 '15 at 14:47

approxiblue

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answered Sep 18 '15 at 13:25

tania_S

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score 8 · Answer 4 · answered Sep 24 '15 at 16:20

It also posible string replacement with stringByReplacingCharactersInRange:withString:

for (int i = 0; i < card.length - 4; i++) {

    if (![[card substringWithRange:NSMakeRange(i, 1)] isEqual:@" "]) {

        NSRange range = NSMakeRange(i, 1);
        card = [card stringByReplacingCharactersInRange:range withString:@"*"];

    }

} //out: **** **** **** 1234

score 0 · Answer 5 · edited Jun 09 '17 at 09:16

0

NSString *stringreplace=[yourString stringByReplacingOccurrencesOfString:@"search" withString:@"new_string"];

edited Jun 09 '17 at 09:16

alfonoso

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answered Apr 18 '17 at 10:37

Shaik Tamim

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Please use the [edit] link to explain how this code works and don't just give the code, as an explanation is more likely to help future readers. See also [answer]. [source](http://stackoverflow.com/users/5244995) – Jed Fox Jun 09 '17 at 15:00

score 0 · Answer 6 · answered Apr 02 '12 at 06:23

The problem exists in old versions on the iOS. in the latest, the right-to-left works well. What I did, is as follows:

first I check the iOS version:

if (![self compareCurVersionTo:4 minor:3 point:0])

Than:

// set RTL on the start on each line (except the first)  
myUITextView.text = [myUITextView.text stringByReplacingOccurrencesOfString:@"\n"
                                                           withString:@"\u202B\n"];

String replacement in Objective-C

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