- JavaScript has a single Number object to store numeric values; behind the scenes, it only uses floating points ("floats"), even if it seems to use integers (it simply omits the ".0" after it).
- There are four ways to declare a number - first, by using the Number object's constructor:
var num = new Number(); // zero, by default
var year = new Number(2024); // integer
var Pi = new Number(3.14); // floating point - Just declare a variable, and assign a numeric value to it:
var num = 3; // Assign integer
num = 7.713; // Now assign a float number - Directly use your number, as a "numeric literal":
alert( "Our total is " + (7+5) ); // No memory allocation for variable! - Store or display the numeric value returned by a method; the indexOf() method checks if a character is found in a string in this snippet, and returns the character position index (integer).
var str = "I learn JavaScript and it's fun";
var num = str.indexOf("n");
alert( num ); // 6 → position index of first 'n' Tip: you can check for numeric values in variables with the isNaN() function.
And you can extract integers or floating points from strings, using parseInt() or parseFloat().
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