seen from Japan
seen from China
seen from Finland
seen from United States

seen from Netherlands

seen from China
seen from United States
seen from Japan
seen from United States

seen from United States
seen from China
seen from Russia
seen from United States
seen from Finland
seen from Malaysia
seen from United States
seen from France
seen from United States
seen from Canada
seen from United States
The "use strict" directive was new in ECMAScript version 5. It is not a statement, but a literal expression, ignored by earlier versions of JavaScript. The purpose of "use strict" is to indicate that the code should be executed in "strict mode". With strict mode, you can not, for example, use undeclared variables. All modern browsers support "use strict" except Internet Explorer 9 and lower: You can use strict mode in all your programs. It helps you to write cleaner code, like preventing you from using undeclared variables.