Programmer Think

Let and const are newly added commands in ES6 to declare variables. These two commands are different from var in ES5, and let and const are slightly different The difference between var and let/const Block level scopeThere is no variable promotionTemporary dead zoneNon repeatable declarationThe global variables declared by let and const ...

1. Constant expression The so-called constant expression refers to an expression composed of multiple (≥ 1) constants. In other words, if the members in the expression are constants, the expression is a constant expression. That is, once the constant expression is determined, its value is not allowed to be changed. The execution proces ...