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JavaScript: Number function

Description

The number function is used to converts a specified object to a number.

Syntax

Number(obj)

Parameters

obj: Required. An object.

Note: If the object is a Date object the function returns a value in milliseconds calculated from 01 January, 1970 UTC (GMT). The return value is positive if the given date is after the said date and negative if before the said date.

If the object is a string and if there is no well-formed numeric literal the function returns NaN.

Example of Number() function

The following example demonstrates how to use Number() function.

JavaScript Code:

var str1 = "4400.23";
var num1 = Number(str1);
console.log('"4400.23" converted to : '+num1);

View the example in the browser

Live demo:

See the Pen number-function-1 by w3resource (@w3resource) on CodePen.


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Next: JavaScript: String function



JavaScript: Tips of the Day

semicolon (;)

function nums(a, b) {
  if (a > b) console.log('a is bigger');
  else console.log('b is bigger');
  return;
  a + b;
}

console.log(nums(4, 2));
console.log(nums(1, 2));

In JavaScript, we don't have to write the semicolon (;) explicitly, however the JavaScript engine still adds them after statements. This is called Automatic Semicolon Insertion. A statement can for example be variables, or keywords like throw, return, break, etc.
Here, we wrote a return statement, and another value a + b on a new line. However, since it's a new line, the engine doesn't know that it's actually the value that we wanted to return. Instead, it automatically added a semicolon after return. You could see this as:

return;
a + b;
This means that a + b is never reached, since a function stops running after the return keyword. If no value gets returned, like here, the function returns undefined. Note that there is no automatic insertion after if/else statements!

Ref: https://bit.ly/3jFRBje