Introduction to JavaScript
The very first step to learning JavaScript (JS) is to learn the syntax and understand the syntax of JavaSript.
var a, b, c; //declare variables
a = 25; //assign
b = 65; //assign
c = a+b; // computeString
The string can be written with double or single quotes:
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Strings Learn TutorialsLink</h2>
<p>Strings can be written with double or single quotes in JavaScript</p>
<p id="TL"></p>
<script>
document.getElementById("TL").innerHTML = 'Rajib';
</script>
</body>
</html>Variables
In any programming language, the purpose is to store values in a variable, thus here too in JavaScript values are stored.
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Variables TutorialsLink</h2>
<p>In this example, A is defined as a variable.
Then, A is assigned the value of 100:</p>
<p id="TL"></p>
<script>
var A;
A = 100;
document.getElementById("TL").innerHTML = A;
</script>
</body>
</html>
Operators
Arithmetic Operators are used to performing mathematical operations.
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Operators TutorialsLink</h2>
<p>JavaScript uses arithmetic operators to compute values.</p>
<p id="TL"></p>
<script>
document.getElementById("TL").innerHTML = (45 + 56) * 210;
</script>
</body>
</html>
Comments
Code after double slashes // or between /* and */ is treated as a comment in JavaScript.
<!DOCTYPE html>
<html>
<body>
<h1>JavaScript Comments are Not Executed</h1>
<p id="TL"></p>
<script>
var A;
A = 78;
// A = 22; I will not be executed because it is a comment
document.getElementById("TL").innerHTML = A;
</script>
</body>
</html>
