Function Overload in TypeScript

• We can have a function with same name, but different parameters and different functionality. This is known as Function Overload.
• We can first declare the functions and then define it.
• If they differ on the number of parameters, we can mark the parameters as optional during function definition.
• Please note that this function overloading is different from C# function overloading. There we used to have many function definitions with one function name; but here, we have only one function definition.
• Based on our inputs, your code will choose which function to invoke.
• We can differentiate our functions based on
  • Data Types of the parameters
  • Number of Parameters
  • Sequence of Parameters

Below is a sample code

function addition(num1:number, num2:number):void;
function addition(str1:string,str2:string):void;

function addition(a:any, b:any):void{
    console.log(a+b);
}

addition("Hello", " Friends");
addition(10,20);

Below is the output of above code:

Other Related Articles

Functions in TypeScript
Parameterized Functions – Part 1
Parameterized Functions – Part 2