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Introduction to JavaScript: A Beginner’s Guide

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Shedrach Musa
·

3 min read

Table of Content

  • What is JavaScript

  • JavaScript syntax

  • JavaScript Datatypes

  • JavaScript control structure

JavaScript is one of the most popular programming languages in the world. It is a versatile language that is used for both client-side and server-side programming.

JavaScript is a powerful tool for web developers. It allows them to create dynamic, interactive web pages that can respond to user input.
In this article, we’ll cover the basics of JavaScript, including its syntax, data types and control structures.

What is JavaScript

JavaScript is a programming language that was first created in 1995 by Brendan Eich. Originally, it was designed to be a scripting language for web browsers, allowing web developers to create dynamic and interactive web pages. Today, JavaScript is used for a wide range of purposes, including building web applications, creating mobile apps and even powering robots and drones.

JavaScript Syntax

JavaScript is a high-level programming language. Its syntax is similar to other programming language like Java and C++.
Here is an example of a simple JavaScript program

const greeting = "Hello world";
console.log(greeting);

In this example, we define a variable called ‘greeting’ and set its value to the string ‘Hello world’. We then use the ‘console.log()’ function to output the value of the variable ‘greeting’ to the console.

JavaScript Data Types

JavaScript supports several data types including strings, numbers, boolean, arrays and objects.

Here is a brief explanation of each data type:

  • String: A sequence of characters enclosed in quotes such as ‘Hello world’.

  • Number: A numerical value. It can be a whole number or a decimal such as 23, 3.25.

  • Boolean: A true or false value

  • Arrays: A list of values enclosed in a square bracket and separated by commas such as [1, 2, 3]

  • Objects: A collection of key-value pairs enclosed in curly braces such as {name: ‘Musa’, age: 25}.

JavaScript Control Structures

JavaScript provides several control structures that allow you to control the flow of your program.

Here are a few examples

  • if/else statements: These allow you to execute a block of code if a certain condition is met or a different block of code if the condition is not met. An example can be seen below
let number = 5;
if(number>10){
console.log('number is greater than 10');
}
else{
console.log('number is less than 10');
}

In this example, we define a variable called ‘number’ and set its value to 5. we then use an if/else statement to check if the ‘number’ is greater than 10. Since it is not, we execute the code in the ‘else’ block, which outputs ‘number is less than 10’ to the console.

  • Loops: This allows you to execute a block of code multiple times. Here is an example of a for loop:
for (let i = 0; i < 5; i++){
console.log(i)}

In this example, we use a for loop to output the numbers 0 to 4 to the console. The loop starts with ‘i’ set to 0 and then continues as long as ‘i' is less than 5. Each time the loop executes, we output the value of ‘i’ to the console and then increase it by 1.

Conclusion

JavaScript is a powerful and versatile programming language that is essential for web developers to create dynamic and interactive web pages.

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