JavaScript Function Invocation
Last Updated :
02 Jun, 2023
The JavaScript Function Invocation is used to execute the function code and it is common to use the term “call a function” instead of “invoke a function”. The code inside a function is executed when the function is invoked.
Syntax:
- Invoking a Function as a Function:
function myFunction( var ) {
return var;
}
myFunction( value );
- Invoking a Function as a Method:
let myObject = {
let : value,
functionName: function () {
return this.let;
}
}
myObject.functionName();
Parameters: It contains two parameters as mentioned above and described below:
- functionName: The functionName method is a function and this function belongs to the object and myObject is the owner of the function.
- this: The parameter this is the object that owns the JavaScript code and in this case the value of this is myObject.
Example 1: This example uses function invocation to add two numbers.
html
<!DOCTYPE html>
<html lang="en">
<head>
<title>JavaScript Function Invocation</title>
</head>
<body style="text-align:center;">
<h2 style="color:green">GeeksForGeeks</h2>
<h4>JavaScript Function Invocation</h4>
<p>
Function returns the addition
of 50 and 60
</p>
<p id="geeks"></p>
<script>
function myFunction(a, b) {
return a + b;
}
document.getElementById("geeks").innerHTML
= window.myFunction(50, 60);
</script>
</body>
</html>
|
Output:
Example 2: This example uses function invocation to concatenate strings.
Javascript
let myObject = {
firstName: "Geeks",
middleName: "for",
lastName: "Geeks",
fullName: function () {
return this.firstName + this.middleName
+ this.lastName;
}
}
console.log(myObject.fullName());
|
