Should I 'use strict' for every single javascript function I write?

Question

Should I \'use strict\' for every single javascript function I write?

What is a good practice to use strict in a large AngularJS project? Using it globally can break

Answer 1

All code you write¹ should be in strict mode. It helps you catch mistakes by not ignoring exceptions.

However, no, this does not mean that you need to prepend "use strict"; to every function definition, you only should put it in the module scope - once per file - so that it is inherited by all your functions. When you're going to switch to ES6 modules it will be implied anyway.

_{1: I'd even argue for enabling it globally, as strict mode should not break any properly written code.
If it does break a third party script, the solution might not be to disable strict mode again…}