JavaScript Advanced (1)---operator

JavaScript operators

1. The comparison between "= = =" and "= =" in JavaScript

In short: the "= = =" Requirement type is equal to the value.

"= =" Requires only equal values

var num_str= "1";  // Num_str is a character variable num_str   = =  1; // result is true  = = = 1; // the values are the same, but the types are different. The result is false1===1; // value is the same as type, return true1===2;// type Same, value different, return false

2, about "| |" With the "&&" logical character

With a| | B and C&&d

A and B need only one to be true and the whole to be true

C and D only need to have one false, then the overall value is False

Note: If A is true, then part B will not need to be executed .

　　　　　if C is false, then part D does not need to be executed .

　　　　　　(JavaScript is not performed by default)

2. Precedence between operators　　　

　　arithmetic Operators > comparison operators > logical Operators > assignment equals "="

JavaScript Advanced (1)---operator