js Function type_javascript skills

1. A function is an object, and the function name is a pointer to the function object and will not be bound to a function.
2. The function is not overloaded (function overloading: the same function name corresponds to the implementation of multiple functions.)
For Example:
　function addnum(num){return num 10}
　function addnum(num){return num 20}
addnum(10);//30
3. Function expression and function declaration (the parser will read the function declaration first, other situations are equivalent).
4. As a function of value.
Sort the object array according to an object attribute?