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# Hello World
Deno is a secure runtime for both JavaScript and TypeScript. As the hello world
examples below highlight the same functionality can be created in JavaScript or
TypeScript, and Deno will execute both.
## JavaScript
In this JavaScript example the message `Hello [name]` is printed to the console
and the code ensures the name provided is capitalized.
**Command:** `deno run hello-world.js`
```js
function capitalize(word) {
return word.charAt(0).toUpperCase() + word.slice(1);
}
function hello(name) {
return "Hello " + capitalize(name);
}
console.log(hello("john"));
console.log(hello("Sarah"));
console.log(hello("kai"));
/**
* Output:
*
* Hello John
* Hello Sarah
* Hello Kai
**/
```
## TypeScript
This TypeScript example is exactly the same as the JavaScript example above, the
code just has the additional type information which TypeScript supports.
The `deno run` command is exactly the same, it just references a `*.ts` file
rather than a `*.js` file.
**Command:** `deno run hello-world.ts`
```ts
function capitalize(word: string): string {
return word.charAt(0).toUpperCase() + word.slice(1);
}
function hello(name: string): string {
return "Hello " + capitalize(name);
}
console.log(hello("john"));
console.log(hello("Sarah"));
console.log(hello("kai"));
/**
* Output:
*
* Hello John
* Hello Sarah
* Hello Kai
**/
```
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