变量名称作为Javascript中的字符串

Question

有没有办法在Javascript中将变量名称作为字符串？(比如Cocoa中的NSStringFromSelector)

我想这样做:

var myFirstName = 'John';
alert(variablesName(myFirstName) + ":" + myFirstName);

--> myFirstName:John

- 添加

我正在尝试使用JavaScript连接浏览器和其他程序.我想将实例名称从浏览器发送到另一个程序以获取回调方法.

FooClass = function(){};
FooClass.someMethod = function(json) {
  // Do something
}

instanceA = new FooClass();
instanceB = new FooClass();
doSomethingInAnotherProcess(instanceB); // result will be substituted by using instanceB.someMethod();

...

....

[来自其他节目]

evaluateJavascriptInBrowser("(instanceName).someMethod("resultA");");

在PHP中:如何在PHP 中将变量名称作为字符串？

Answer 1

像Seth的回答一样,但Object.keys()改为使用:

const varToString = varObj => Object.keys(varObj)[0]

const someVar = 42
const displayName = varToString({ someVar })
console.log(displayName)

Answer 2

通常,您可以将哈希表用于要将名称映射到某个值的情况,并且能够检索两者.

var obj = { myFirstName: 'John' };
obj.foo = 'Another name';
for(key in obj)
    console.log(key + ': ' + obj[key]);

Answer 3

您可以使用以下解决方案来解决您的问题:

const myFirstName = 'John'
Object.keys({myFirstName})[0]

// returns "myFirstName"

Answer 4

在ES6中,您可以编写如下内容:

let myVar = 'something';
let nameObject = {myVar};
let getVarNameFromObject = (nameObject) => {
  for(let varName in nameObject) {
    return varName;
  }
}
let varName = getVarNameFromObject(nameObject);

不是最好看的东西,但它完成了工作.

这利用了ES6的对象解构.

更多信息:https://hacks.mozilla.org/2015/05/es6-in-depth-destructuring/

Answer 5

var x = 2;
for(o in window){ 
   if(window[o] === x){
      alert(o);
   }
}

但是,我认为你应该像"karim79"那样做

Answer 6

这适用于基本表达式

const nameof = exp => exp.toString().match(/[.](\w+)/)[1];

例

nameof(() => options.displaySize);

片段:

var nameof = function (exp) { return exp.toString().match(/[.](\w+)/)[1]; };
var myFirstName = 'Chuck';
var varname = nameof(function () { return window.myFirstName; });
console.log(varname);

Answer 7

为了安全起见，pop可能比用[0]索引更好（为了安全起见，变量可能为null）。

const myFirstName = 'John'
const variableName = Object.keys({myFirstName}).pop();
console.log(`Variable ${variableName} with value '${variable}'`);

// returns "Variable myFirstName with value 'John'"

Answer 8

从任何有效的 Javascript（变量、类）中获取字符串：

const nameOf = (f) => (f).toString().replace(/[ |\(\)=>]/g,'');

例子：

nameOf(() => myVariable)             // myVariable
nameOf(() => myVariable.name)        // myVariable.name
nameOf(() => myVariable.name.length) // myVariable.name.length
nameOf(() => myVariable.name[10])    // myVariable.name[10]
nameOf(() => MySuperClass)           // MySuperClass

Answer 9

var somefancyvariable = "fancy";
Object.keys({somefancyvariable})[0];

这不能成为函数,因为它返回函数变量的名称

// THIS DOESN'T WORK
function getVarName(v) {
    return Object.keys({v})[0];
}
// Returns "v"

Answer 10

到目前为止，我发现将变量名称作为字符串获取的最短方法：

const name = obj => Object.keys(obj)[0];

const whatsMyName = "Snoop Doggy Dogg";

console.log( "Variable name is: " + name({ whatsMyName }) );
//result: Variable name is: whatsMyName

Answer 11

从ECMAScript 5.1开始,您可以使用Object.keys从对象中获取所有属性的名称.

这是一个例子:

// Get John’s properties (firstName, lastName)
var john = {firstName: 'John', lastName: 'Doe'};
var properties = Object.keys(john);

// Show John’s properties
var message = 'John’s properties are: ' + properties.join(', ');
document.write(message);

Answer 12

使用 Object.keys() 的最佳方法；

示例：用于在全局范围内获取多变量名称

// multi variables for testing
var x = 5 , b = true , m = 6 , v = "str";

// pass all variables you want in object
function getVarsNames(v = {}){
    // getting keys or names !
    let names = Object.keys(v);
    // return array contain all names of variables 
    return names;
}

// testing if that work or not 
let VarsNames = getVarsNames({x , b , m , v});

console.log(VarsNames); // output is array [x , b , m , v]