var a = NaN;
switch(a) { case NaN: alert("It's not a number);}
为何case匹配失败?
console.log(isNaN(NaN));//true
想起来了,NaN和自身不相等
var a = NaN;
switch(a) { case NaN: alert("It's not a number);}
为何case匹配失败?
console.log(isNaN(NaN));//true
想起来了,NaN和自身不相等