Javascript:在运行时创建函数

Question

更新

解决方案适用于 foreach 循环，但不适用于 for 循环

function x(number){
  return number - 10;
}
var i = 0
var runtimefunctions = {};
var allLevels = {"1":"State","2":"Educational_Services","3":"Principal_Networks","4":"Schools"}
 for (var key in allLevels) {
   runtimefunctions[i] = function() { return x(i); };
i++;
};

console.log(runtimefunctions[1]()); // -6
console.log(runtimefunctions[2]()); // -6
console.log(runtimefunctions[3]()); // -6

<小时/>

努力制作函数，但这是第一次创建这样的东西，所以无法理解正确的方法......

我有一个函数..

function x(number){
return number - 10;
}
runtimefunctions = {};
now I have a loop to run
[1,2,3].forEach(function(y){
   //here I want to create a function.. which will make a function x(y) -- like this
   runtimefunctions[x] = new Function("return function x_" + levelIterator + "(levelIterator){ console.log(levelIterator); x(" + y + ") }")();

});

所以基本上..想要制作这样的功能。

runtimefunctions= {
 "1": x(1),
 "2": x(2),
and so on
}

Answer 1

这是您需要的吗？

function x(number){
  return number - 10;
}

var runtimefunctions = {};

[1,2,3].forEach(function(y){
   runtimefunctions[y] = function() { return x(y); };
});

console.log(runtimefunctions[1]()); // -9
console.log(runtimefunctions[2]()); // -8
console.log(runtimefunctions[3]()); // -7

<小时/>

为了满足您的下一个(for-in)要求，您需要通过附加函数调用来关闭索引变量:

var runtimefunctions = {}, i = 0;
var allLevels = {"1":"State","2":"Educational_Services","3":"Principal_Networks","4":"Schools"}
for (var key in allLevels) {
  runtimefunctions[i] = function(index){ return function() { return x(index); } }(i++);
};