“use strict” What does this mean in Javascript

In this blog post we are going learn about "use strict"; and it use in javascript. "use strict"; helps to run our javascript in Strict Mode. It is new feature in ECMAScript 5 that allows us to place a program, or a function, in a “strict” operating context. This strict context prevents certain actions from being taken and throws more exceptions. It is not a statement, but a literal expression, ignored by earlier versions of JavaScript. It’s time to start using JavaScript strict mode Strict ...