Call Swift function with multiple arguments form Objective-C syntax

Question

From Objective-C, to call a a Swift function with one argument you have to use bracket syntax and do something I've always found confusing: Add the word "With" before the argument and capitalize the argument label as in:

//swift extension

@objc public func getImageCalled(name: String?) -> UIImage? {
}

//Called from Objective-C
 ImageClass *imgObject = [[ImageClass alloc] init];
 UIImage * img = [imgObject getImageCalledWithName:myname];

How do you do this with two arguments as in:

@objc public func getImageCalled(name: String?,width:Int?) -> UIImage? {
}

[imgObject getImageCalledWithName:myname WithWidth:30]; is not working for me.

Does your Swift code compile at all? There should be an error message “Method cannot be marked @objc because the type of the parameter 2 cannot be represented in Objective-C” — Martin R
– Martin R, Commented Oct 14, 2020 at 20:47
The With<NameOfFirstParameter> is only a convention for the first argument, all subsequent arguments are just named the same. It originates from Objective-C where you don't specify a named argument for the first parameter due to its syntax. — Claus Jørgensen
– Claus Jørgensen, Commented Oct 14, 2020 at 22:01

Shehata Gamal · Accepted Answer · 2020-10-14 20:45:41Z

3

You can try

[imgObject getImageCalledWithName:myname width:30];

answered Oct 14, 2020 at 20:45

Shehata Gamal

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