消除了在call（）调用的函数内部编写“ this”的需要？

Question

I want to be able to write expressions as strings and then evaluate them. So I have:

var expression  = "this.num*2"
function x(expression, o) {
  var fn = function(){}, result;
  fn = Function.apply(o, ["return " + expression + " ;"]);
  return fn.call(o)
}

var obj = {"num":3}
console.log(x(expression, obj))

Which works great. However, I want to be able to write "num*2"

How do I do this?

Answer 1

您可以尝试使用JavaScript Expression Evaluation库 ，该库允许执行Parser.evaluate("num * 2", {num: 3}) 。