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Kavya S
Kavya S

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Day 3 - JavaScript

Function in JavaScript

In Javascript,a function is a reusable block of code that can be defined and then executed whenever needed.

Syntax

function name(){
console.log("Hello");
}
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What will be the output of above Code?

Nothing,it will not Print Anything. Why? because we have not called this function. Let’s see how to do this.

function fn(){
console.log("Hello");
}
fn();
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  • Function Keyword - The function keyword is used to create the function.

  • Function Name - The name of the function is fn, followed by parentheses ().

  • Function Body - The code that is executed when we call the function. In our case, it is console.log("Hello");

Function parameters 

function sayhello(name){
console.log("Hello",name);
}
sayhello("kavya"); //Output: hello kavya
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  • Parameter (name) → The variable inside the function definition.
  • Argument ("kavya") → The actual value passed when calling the function.

a function can have multiple parameters

function sayhello(name){
console.log(name);
}
sayhello(); //Output: undefined
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if no value is passed for a parameter,it becomes undefined

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