> To prevent these mistakes from happening, add 'use strict'; at the beginning of your JavaScript files. This enables a stricter mode of parsing JavaScript that

> To prevent these mistakes from happening, add 'use strict'; at the beginning of your JavaScript files. This enables a stricter mode of parsing JavaScript that prevents accidental global variables. I don't think using strict will prevent accidental global variables, such as this.var in global scoped function calls. Strictness main goal is to prevent inadvertently misspelled variables from going unnoticed.