Confuse terms in Angular JS tutorial <p>I'm following a tutorial and I have difficulties to understand a certain sentence which talks about the problem that can occur when naming my properties in Angular:</p> <blockquote> <p>It quietly tolerates all property access errors, including nested properties on nonexistent parents and out-of-bounds array access.</p> <p>aliasing variables as a way to cope with variable shadowing</p> </blockquote> <p>My english is good enough to know what is written, but I really don't understand what is "nested properties on nonexistent parents" and "aliasing variables as a way to cope with variable shadowing". I did some research, but couldn't clearly understand.</p> <p>Could someone give me a clear explanation?</p>