CODEWITHSUNDEEP
typescript
Aditya Thakur
Aditya Thakur

Reputation: 2610

Typescript gives error during runtime but not on compile time

I am trying to learn Typescript, and can't seem to find the issue with my code, i tried searching but couldn't find any relevant material related to my issue. Here's my code:- 

<code>
class Hello{
    lars: string;

    constructor(name: string) {
        this.lars = name;
    }

    sayHello(){
        return `hello ${this.lars}`;
    }
}

let b = new Hello('Metallica');
</code>

i compile the code using the tsc test.ts, it compiles with no errors, but when i run it using node test.ts, it gives me following error:

<blockquote>

lars: string;
        ^

SyntaxError: Unexpected token :
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:616:28)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Function.Module.runMain (module.js:693:10)
    at startup (bootstrap_node.js:188:16)
    at bootstrap_node.js:609:3
</blockquote>

The file runs when i user Node test.js, but don't get the expected output i.e "Hello Metallica", while node test.ts fails.

Here's the compiled code:-

var Hello = /** @class */ (function () {
    function Hello(name) {
        this.lars = name;
    }
    Hello.prototype.sayHello = function () {
        return "hello " + this.lars;
    };
    return Hello;
}());
var b = new Hello('Metallica');

Upvotes: 0

Views: 1294

Answers (1)

Philip Bijker
Philip Bijker

Reputation: 5115

There's nothing wrong with the typescript. You're not seeing the expected result because:

  1. You can't run the typescript. Typescript should be compiled to javascript, which then can be run by for example node. You should run node test.js
  2. There is no line which logs to the console. Try changing the last line to console.log(new Hello('Metallica').sayHello()); for example.

Upvotes: 1

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