When writing the code, in order to save trouble, I wrote this line:
switch（n）{
case 1:
console.log(1);
break;
case 2||3||4:
(In order to save trouble, because the same code block is executed when 2, 3, and 4)
console.log(222);
break;
case 1:
console.log(1);
break;
default:
}
As a result, when n=2 or 3 or 4, the result is all 1. Confused. Still an online question.
Later found the reason:
The case should be followed by a variable. When n is 2, 3, 4, the result of (2||3||4) is true. case true is equivalent to case 1.
For convenience, you can write it like this:
case 2:
case 3:
case 4：
console.log(222)
As long as it does not break out, the code will continue to execute according to the current conditions .
A mistake, blame yourself for being too careless!