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Syntax and Variables

Basics of TypeScript: Syntax and Variables

TypeScript, developed by Microsoft, is a superset of JavaScript that primarily provides optional static typing, classes, and interfaces. One of the big benefits is to enable IDEs to provide a richer environment for spotting common errors as you type the code. In this article, we'll be taking an introductory look at TypeScript's syntax and how to use variables.

TypeScript Syntax​

The syntax of TypeScript is a set of rules that define how programs written in TypeScript language are constructed. The TypeScript syntax is pretty much the same as JavaScript syntax. However, TypeScript introduces new features and concepts not seen in JavaScript.

Here is a simple TypeScript code snippet:

let message: string = 'Hello, World!';
console.log(message);

In the above example, we have a variable message of type string. The type is explicitly declared using the : symbol. The variable is initialized with the string 'Hello, World!'. The console.log(message) statement prints the value of the message.

Variables​

Variables are the building blocks of any language. They are used to store data, which can be manipulated later on in the program. In TypeScript, you can declare a variable using var, let, or const keywords.

Here's how you declare variables in TypeScript:

let name: string = 'John Doe';
const age: number = 25;
var isStudent: boolean = false;

In the code snippet above, we've declared three variables:

  • name of type string.
  • age of type number.
  • isStudent of type boolean.

Variable Types​

TypeScript provides different types to help you make the most of your variables.

Here are the main types:

  • number: For numerical values.
  • string: For textual data.
  • boolean: For true/false values.
  • null: Represents a null value.
  • undefined: Represents value that is not assigned.

You can also have variables of type any which are dynamic and can hold different types of values.

let dynamicVariable: any = 'Hello';
dynamicVariable = 100;
dynamicVariable = true;

In the code snippet above, dynamicVariable is of type any. It can hold different types of values.

Conclusion​

Understanding the basics of TypeScript syntax and how to use variables is fundamental to using TypeScript effectively. We've covered the basics in this article, but there's still much to learn. Keep on practicing and experimenting with variables and types, and you'll get the hang of it in no time.

Remember, the only way to learn a new language is to write in it, so make sure you're coding along as you read this. Happy TypeScripting!