This works fine, we all know that:
开发者_运维问答NSString *textoutput = @"Hello";
outLabel.text = textoutput;
However, what if you want to include a variable inside that NSString
statement like the following:
NSString *textoutput =@"Hello" Variable;
In C++ I know when I cout
something and I wanted to include a variable all I did was soemthing like this:
cout << "Hello" << variableName << endl;
So I'm trying to accomplish that with Objective-C but I don't see how.
You can do some fancy formatting using the following function:
NSString *textoutput = [NSString stringWithFormat:@"Hello %@", variable];
Note that %@
assumes that variable
is an Objective-C object. If it's a C string, use %s
, and if it's any other C type, check out the printf
reference.
Alternatively, you can create a new string by appending a string to an existing string:
NSString *hello = @"Hello";
NSString *whatever = [hello stringByAppendingString:@", world!"];
Note that NSString
is immutable -- once you assign a value, you can't change it, only derive new objects. If you are going to be appending a lot to a string, you should probably use NSMutableString
instead.
I have The Cure you're looking for, Robert Smith:
if your variable is an object, use this:
NSString *textOutput = [NSString stringWithFormat:@"Hello %@", Variable];
The '%@' will only work for objects. For integers, it's '%i'.
For other types, or if you want more specificity over the string it produces, use this guide
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