Setting the default parameter values for a JavaScript function

In this tutorial, we are going to learn about how to set default parameter values to a function in JavaScript.

Default function parameters are introduced in es6, which help us to initialize the parameter with a default value.

Note: In JavaScript, if we don’t pass any value to function parameters, it will be initialized with a value undefined.

Setting the default parameter values

We can set the default parameter values to a function at the time of declaring it.

Here is an example, that adds the default value to a name parameter:

function enterYourname(name="Unknown"){
    return 'User name is '+ name
}

console.log(enterYourname());

Second example:

function addFive(a,b=5){
    return a+b;
}

console.log(addFive(1));

Output:

6