April 2, 2019

Declare Keyword in Typescript for Missing Type Definition File

In this tutorial, you will learn how to use declare keyword to get rid of compilation errors in case of missing type definition file for any javascript library. I have tried my best to keep it pure basic and simple as much as possible.

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    
    <!-- Javascript Library -->
    <script src="employee.js"></script>
    <script src="index.js"></script>
</body>
</html>

index.ts

declare var printName:any;

printName('James');

employee.js

const printName = (name) =>{
    console.log(name);
};

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