CODEWITHSUNDEEP
iphoneobjective-cnsmutablearraynsmutablestring
Pooja
Pooja

Reputation: 2200

error : 'Attempt to mutate immutable object with appendString:' --

I am getting an error 'Attempt to mutate immutable object with appendString:'

and my code is 

NSMutableString *resultString= [[NSMutableString alloc]init];


for (NSMutableString *s in self.ArrayValue)
{
    [resultString appendString:s];
    NSLog(resultString);

}

ArrayValue is NSMutableArray.
I am not able to understand where is the problem

thank you in advance

Upvotes: 3

Views: 6673

Answers (3)

makboney
makboney

Reputation: 1824

    ArrayValue = [NSMutableArray arrayWithObjects:@"b",@"o",@"n",nil];
NSMutableString *resultString= [[NSMutableString alloc]init];

for (NSMutableString *s in self.ArrayValue)
{
    [resultString appendString:s];
    NSLog(resultString);

}

works for me..

Upvotes: 2

JeremyP
JeremyP

Reputation: 86651

As posted, the code you have will not give you the error you describe. Probably, somewhere between allocating resultString and the for loop, you are overwriting it with a normal NSSring.

Upvotes: 7

Ajay Sharma
Ajay Sharma

Reputation: 4517

Just do have like this:

It works for me...

    NSMutableString *resultString= [[NSMutableString alloc]init];
NSMutableArray *ArrayValue=[[NSMutableArray alloc]init];
[ArrayValue addObject:@"One"];
[ArrayValue addObject:@"Two"];
[ArrayValue addObject:@"Three"];

for (NSMutableString *s in ArrayValue)
{
    [resultString appendString:s];
    NSLog(@"%@",resultString);------->You should use %@ to print the string otherwise will show your warning.

}

O/P on Console:

2011-03-08 19:13:02.243 iPadMables[4557:207] One

2011-03-08 19:13:06.224 iPadMables[4557:207] OneTwo

2011-03-08 19:13:09.388 iPadMables[4557:207] OneTwoThree

Upvotes: 2

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