Calling external js function from Angular 5 not working

Question

I called hello function from ts file but I got error like hello is not defined.

hello.js

function hello() {
    alert("Hello.......!");
}

index.html

<script src="./assets/js/hello.js"></script>

component.ts

declare var hello: any;

// calling on load
let result = hello();

console.log(result);

Answer 1

Include your JS file in angular-cli.json file under scripts array

"scripts": [

]

make sure to put the correct relative URL. And then you can simply use it in your ts file. Make sure to restart ng serve if you are using it.