另一种通过引用传递任何(局部的，基本的)变量的方法是通过eval“动态”地用闭包包装变量。这也适用于“use strict”。(注意:注意eval对JavaScript优化器不友好，并且变量名周围缺少引号可能会导致不可预测的结果)

"use strict"

// Return text that will reference variable by name (by capturing that variable to closure)
function byRef(varName){
    return "({get value(){return "+varName+";}, set value(v){"+varName+"=v;}})";
}

// Demo

// Assign argument by reference
function modifyArgument(argRef, multiplier){
    argRef.value = argRef.value * multiplier;
}

(function(){
    var x = 10;

    alert("x before: " + x);
    modifyArgument(eval(byRef("x")), 42);
    alert("x after: " + x);
})()

现场示例:https://jsfiddle.net/t3k4403w/

如果你想通过引用传递变量，一个更好的方法是通过在对象中传递参数，然后使用window开始更改值:

window["varName"] = value;

例子:

// Variables with first values
var x = 1, b = 0, f = 15;


function asByReference (
    argumentHasVars = {},   // Passing variables in object
    newValues = [])         // Pass new values in array
{
    let VarsNames = [];

    // Getting variables names one by one
    for(let name in argumentHasVars)
        VarsNames.push(name);

    // Accessing variables by using window one by one
    for(let i = 0; i < VarsNames.length; i += 1)
        window[VarsNames[i]] = newValues[i]; // Set new value
}

console.log(x, b, f); // Output with first values

asByReference({x, b, f}, [5, 5, 5]); // Passing as by reference

console.log(x, b, f); // Output after changing values

由于我们没有javascript的引用传递功能，唯一的方法是让函数返回值，并让调用者分配它:

So

"makePretty(myArray[x]);"

应该是

"myArray[x] = makePretty(myArray[x]);"

这是在函数内部需要赋值的情况下，如果只需要突变，那么传递对象并突变它就足够了

撇开“参考资料传递”的讨论不谈，那些仍然在寻找上述问题的解决方案的人可以使用:

const myArray = new Array(var1, var2, var3);
myArray.forEach(var => var = makePretty(var));

I've been playing around with syntax to do this sort of thing, but it requires some helpers that are a little unusual. It starts with not using 'var' at all, but a simple 'DECLARE' helper that creates a local variable and defines a scope for it via an anonymous callback. By controlling how variables are declared, we can choose to wrap them into objects so that they can always be passed by reference, essentially. This is similar to one of the Eduardo Cuomo's answer above, but the solution below does not require using strings as variable identifiers. Here's some minimal code to show the concept.

function Wrapper(val){
    this.VAL = val;
}
Wrapper.prototype.toString = function(){
    return this.VAL.toString();
}

function DECLARE(val, callback){
    var valWrapped = new Wrapper(val);    
    callback(valWrapped);
}

function INC(ref){
    if(ref && ref.hasOwnProperty('VAL')){
        ref.VAL++; 
    }
    else{
        ref++;//or maybe throw here instead?
    }

    return ref;
}

DECLARE(5, function(five){ //consider this line the same as 'let five = 5'
console.log("five is now " + five);
INC(five); // increment
console.log("five is incremented to " + five);
});

像字符串和数字这样的基本类型变量总是按值传递。 数组和对象通过引用或基于以下条件的值传递:

如果你正在设置一个对象或数组的值，它是通过值传递。 Object1 = {prop: "car"}; Array1 = [1,2,3]; 如果你正在改变一个对象或数组的属性值，那么它是引用传递。 中的object1。道具= "汽车"; Array1 [0] = 9;

Code

函数passVar(obj1, obj2, num) { 其中obj1。道具= "笔记本电脑";//将改变原来的 Obj2 ={道具:"电脑"};//不影响原 Num = Num + 1;//不影响原 ｝ Var object1 = { 道具:“车” }; Var object2 = { 道具:“自行车” }; Var number1 = 10; passVar(object1, object2, number1); console.log(中的object1);//输出:对象{道具:"笔记本电脑"} console.log (object2);//输出:Object {prop: "bike"} console.log (number1);//输出:10