javascriptCheck if a string is a valid number

var str = '25.99';
var is_numeric = (typeof str == 'string') && !isNaN(parseFloat(str));ctrl + cyoutubegithub

`var str` declare test string with number	`typeof str == 'string'` ensure `str` is of `string` type
`isNaN(parseFloat(str))` ensure `str` contains valid number