javascript - 使用 Function() 构造函数作为闭包

Question

我正在尝试做这样的事情:

function simpleOperations(operation) {
    let myFanction = new Function('a', 'b', 'a ' + operation + ' b');
    return myFanction
}

let sum = simpleOperations("+")
let multiplicate = simpleOperations("*")

console.log("your sum is: " + sum(3,7));
console.log("your product is: " + multiplicate(3,7));

而不是得到:

your sum is: 10
your product is: 21

我明白了:

your sum is: undefined
your product is: undefined

您对如何解决它有任何想法吗？ :)

Answer 1

函数的正文需要return值，否则你的a + b或a * b等将只是一个未使用的表达式。

function simpleOperations(operation) {
    let myFanction = new Function('a', 'b', 'return a ' + operation + ' b');
    return myFanction
}

let sum = simpleOperations("+")
let multiplicate = simpleOperations("*")

console.log("your sum is: " + sum(3,7));
console.log("your product is: " + multiplicate(3,7));