Append string with variable

问题:

I'm a java guy coming over to Objective-C. In java, to add a variable to a string you'd have to do something along the lines of:

someString = "This string is equal to " + someNumber + ".";

I can't figure out how to do it in Objective-C though. I have an NSMutableString that I'd like to add to the middle of a string. How do I go about doing this?

I've tried:

NSString *someText = @"Lorem ipsum " + someMutableString;
NSString *someText = @"Lorem ipsum " + [someMutableString stringForm];

and a few other things, none of which seem to work. Also interchanged the +s with ,s.

回答1:

You can use appendString:, but in general, I prefer:

NSString *someText = [NSString stringWithFormat: @"Lorem ipsum %@", someMutableString];
NSString *someString = [NSString stringWithFormat: @"This is string is equal to %d.", someInt];
NSString *someOtherString = [NSString stringWithFormat: @"This is string is equal to %@.", someNSNumber];

or, alternatively:

NSString *someOtherString = [NSString stringWithFormat: @"This is string is equal to %d.", [someNSNumber intValue]];

etc...

These strings are autoreleased, so take care not to lose their value. If necessary, retain or copy them and release them yourself later.

回答2:

Try this:

NSMutableString * string1 = [[NSMutableString alloc] initWithString:@"this is my string"];

[string1 appendString:@" with more strings attached"];

//release when done
[string1 release];

回答3:

You need to use stringByAppendingString

NSString* string = [[NSString alloc] initWithString:@"some string"];
string = [string stringByAppendingString:@" Sweet!"];

Don't forget to [string release]; when your done of course.

回答4:

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

[string appendFormat:@"more text %@", object ];