Developing a function that takes a parameter which can be used with or without an additional argument when invoked

Question

Developing a function that takes a parameter which can be used with or without an additional argument when invoked

In my React application, I have a method that accepts a parameter for displaying a modal.

    const displayModal = (p:Result) => {
        setConfirm(true);
        if(p) { //check variable for truthy
            setSelectedRow(p); 
        }    
      }

I need the ability to call this method with or without a parameter. If I try to call it without passing a parameter, my code fails to compile.

    displayModal()

Can anyone suggest a way to modify this method so that it can be called without passing a parameter as well?

javascript reactjs typescript ecmascript-6

Answer 1

Answer №1

If you're working with TypeScript, you have the option to define an optional or default parameter.

You can choose between:

// optional
const displayModal = (p?:Result) => {}

or:

// default
const displayModal = (p:Result = new Result()) => {}
// The value of new Result() can be customized as needed

Both allow you to invoke the function without specifying a parameter.

The main distinction lies in how they handle missing arguments. With optional parameters, the value will be undefined within the function. For default parameters, the function will use the specified default value when no argument is passed.

Answer 2

If you're working with TypeScript, you have the option to define an optional or default parameter.

You can choose between:

// optional
const displayModal = (p?:Result) => {}

or:

// default
const displayModal = (p:Result = new Result()) => {}
// The value of new Result() can be customized as needed

Both allow you to invoke the function without specifying a parameter.

The main distinction lies in how they handle missing arguments. With optional parameters, the value will be undefined within the function. For default parameters, the function will use the specified default value when no argument is passed.

Developing a function that takes a parameter which can be used with or without an additional argument when invoked

Answer №1

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