Removing the front character from NSMutableString

Question

I am trying to remove the front character of a NSMutableString and have tried:

    [str setString: [str substringFromIndex:1]] ,
    [str deleteCharactersInRange:NSMakeRange(0,1)]

and a few others. These two either remove every character or every character except for the one I am trying to remove so for example if I have the String "-2357" and am trying to remove the "-" then I get just the "-" when I should get "2357".

Am I doing something wrong, and how can I fix this?

Show actual code that you think is misbehaving along with logging of the inputs and outputs. — Ken Thomases, May 13 '14 at 06:47
Both lines *do* remove the first character in the string, so what is your real code or question? — Martin R, May 13 '14 at 07:00

score 3 · Answer 1 · edited May 23 '17 at 11:54

3

If you want to use the deleteCharactersInRange method, do this

NSRange range = {0,1};
[str deleteCharactersInRange:range];

Or, you could use substringFromIndex like so:

str = [str substringFromIndex:1];

Contrary to what you are saying, [str deleteCharactersInRange:NSMakeRange(0,1)] should work fine, I don't know why that is not working.

[str substringToIndex:1] will return the string from the beginning to the index 1, which is -. What you want is substringFromIndex. And as this method returns a NSString, you will need to assign it to str; just calling the method on str is not enough.

Edit

Using the deleteCharactersInRange may pose problems for some type of characters. For more information refer to this a question here.

Instead, you can safely use

[str deleteCharactersInRange:[str rangeOfComposedCharacterSequenceAtIndex:0]]

edited May 23 '17 at 11:54

Community

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answered May 13 '14 at 06:32

aksh1t

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I have tried this, it removes all characters from my string and I am left with an empty String. – user3631142 May 13 '14 at 06:49
@user3631142, log the string both before and after. I bet it's not what you think it is. – Ken Thomases May 13 '14 at 06:51
@aksh1t, it's dangerous to remove characters by just assuming they're stand-alone and independent. I recommend `[str deleteCharactersInRange:[str rangeOfComposedCharacterSequenceAtIndex:0]]`. – Ken Thomases May 13 '14 at 06:53
@user3631142 I wish to disagree with you on this. Both of these methods are working perfectly fine. You should try logging the strings before and after like KenThomases suggests. – aksh1t May 13 '14 at 06:57
@Ken Thomases : Thank you for the pointer. I stand enlightened. :) I will edit my answer to update this. – aksh1t May 13 '14 at 06:58

Hgeg · Accepted Answer · 2017-04-27T11:14:58.323

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instead of:

[str substringToIndex:1]

Do this:

[str substringFromIndex:1]

edited Apr 27 '17 at 11:14

answered May 13 '14 at 06:31

Hgeg

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Ya sorry I mistyped I fixed it in my post – user3631142 May 13 '14 at 06:45
It should be substringFromIndex (small letter "s" in "string") – Dani Apr 26 '17 at 10:55

score 1 · Answer 3 · answered May 13 '14 at 06:54

1

If you want to remove first character of the string you can use this:-

string = [string substringFromIndex:1];

answered May 13 '14 at 06:54

Kundan

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Removing the front character from NSMutableString

3 Answers3

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