JavaScript: Maths tutorial code snippet 3.

Number data type: conversion using 'parseFloat()', 'parseInt()' and 'Number()' without the keyword 'new'.

Experiment with using 'minus 0' technique on a string to convert to a number.

Introducing 'typeof()' which returns the type of data that has been passed to it.

Using 'isNaN()' on the data type. Examples of use of above with strings: '42.50', '42.50text' and 'text'.