1.假如有如下for循环
for(
let i = (setTimeout(() => console.log(i),2333),0);
i < 2;
i++
){
}
请问在2333毫秒之后输出几?
2.for...in 佯谬
https://wdd.js.org/i-realy-dont-know-js.html
var scores = [10,11,12];
var total = 0;
for(var score in scores){
total += score;
}
var mean = total/scores.length;
console.log(mean);
3.for in 潜规则
Array.prototype.contains = function(item) {
return this.indexOf(item) >= 0
}
for(let key in [1,2,3,4]) {
console.log(key)
}
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