In Objective-C, you can interpolate strings using the format string syntax with the %@ placeholder to denote where the interpolated string should go. Here's an example:
NSString *name = @"John";
NSString *greeting = [NSString stringWithFormat:@"Hello, %@!", name];
NSLog(@"%@", greeting); // Output: Hello, John!
In the example above, the stringWithFormat: method is used to create a new string by formatting the string with the %@ placeholder, which will be replaced with the value of the name variable.
You can also interpolate multiple values by supplying additional arguments to stringWithFormat:, like this:
NSString *firstName = @"John";
NSString *lastName = @"Doe";
NSString *greeting = [NSString stringWithFormat:@"Hello, %@ %@!", firstName, lastName];
NSLog(@"%@", greeting); // Output: Hello, John Doe!
In this example, the firstName and lastName variables are both included as additional arguments to stringWithFormat:, and are interpolated into the resulting string using the %@ placeholders.