JavaScript

JavaScript?

var x, y;          // How to declare variables

x = 5; y = 6;      // How to assign values

z = x + y;         // How to compute values

Strings are text, written within double or single quotes:

"John Doe"

'John Doe'

var x;

x = 6; // x is assigned the value of 6

The ‘==’ operator tests for abstract equality i.e. it does the necessary type conversions before doing the equality comparison.
But the ‘===’ operator tests for strict equality i.e it will not do the type conversion hence if the two values are not of the same type, when compared, it will return false.

<script>

    // In R.H.S. string "3" is converted into

    // number 3, hence returns true.

    document.write(9 == "9");

    // used for next line

    document.write('<br>')

    // Here no type conversion takes place,

    // hence returns false

    document.write(9 === "9");

</script>

Output:

true

false

Write a simple JavaScript program that on button click displays the current timestamp on screen.

<!DOCTYPE html>

<html>

<body>

<h2>My First JavaScript</h2>

<button type="button"

onclick="document.getElementById('demo').innerHTML = Date()"> // using the Date() function

Click me to display Date and Time.</button>

<p id="demo"></p> // Using the id attribute

</body>

</html>

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