How to execute TypeScript file using command line?
TypeScript is a statically-typed superset of JavaScript that adds optional type annotations and compiles to plain JavaScript. It helps catch errors during development. To execute a TypeScript file from the command line, compile it using tsc filename.ts, then run the output JavaScript file with node.
Syntax:
To check node is installed, run command if not you have to installed it first:
node -v
Now to install typescript, use:
npm install -g typescript
After installing typescript, create a .ts file, for example, greet.ts as given below:
Example:
let greet: string = "Greetings";
let geeks: string = "GeeksforGeeks";
console.log(greet + " from " + geeks);
// save the file as hello.ts Output:
Greetings from GeeksforGeeks
Procedure 1: This typescript file greet.ts will create a javascript file at runtime with the same name. To run any typescript file there are a few ways:
Syntax:
Step 1: First, run the typescript file with the following command. This will create a javascript file from typescript automatically with the same name.
tsc helloWorld.ts
Step 2:Now run the javascript file, the greet.ts file will get executed:
node helloWorld.js
Procedure 2: You can merge both the commands by using a pole | and && like below :
Syntax:
In Windows:
tsc greet.ts | node greet.js
In Linux or MacOS:
tsc helloWorld.ts && node helloWorld.js
Procedure 3: You can also install ts-node along with typescript using the following command:
Syntax:
To install:
npm install -g ts-node
To run:
ts-node helloWorld.ts
Output: Using any of the three ways, the output will remain the same.
Greetings from GeeksforGeeks
