问题 Im confused with how the elem get the value of arr? function lengGreaterThan(num) { function lengGreaterThanNum(elem) { return elem.length > num; } return lengGreaterThanNum; } let arr = ['Justin', 'caterpillar', 'openhome']; console.log(arr.filter(lengGreaterThan(6))); 回答1: That is a really confusing way of writing it, but essentially you are just putting a function that takes one parameter into the filter function. This here would do the same thing: console.log(arr.filter((elem) => { return