const text = '{"name":"John", "age":30, "city":"New York"}';
const myArr = JSON.parse(text);
document.getElementById("demo").innerHTML = myArr.name;

你需要使用JSON.parse()将String转换为Object:

var obj = JSON.parse('{ "firstName":"name1", "lastName": "last1" }');

下面是我处理一些边缘情况的方法，比如将空格和其他基本类型作为值

const str = " c:234 , d:sdfg ,e: true, f:null, g: undefined, h:name "; 

const strToObj = str
  .trim()
  .split(",")
  .reduce((acc, item) => {
    const [key, val = ""] = item.trim().split(":");
    let newVal = val.trim();

    if (newVal == "null") {
      newVal = null;
    } else if (newVal == "undefined") {
      newVal = void 0;
    } else if (!Number.isNaN(Number(newVal))) {
      newVal = Number(newVal);
    }else if (newVal == "true" || newVal == "false") {
      newVal = Boolean(newVal);
    }
    return { ...acc, [key.trim()]: newVal };
  }, {});

在你的情况下

var KeyVal = string.split(", ");
var obj = {};
var i;
for (i in KeyVal) {
    KeyVal[i] = KeyVal[i].split(":");
    obj[eval(KeyVal[i][0])] = eval(KeyVal[i][1]);
}

这个简单的方法…

var string = "{firstName:'name1', lastName:'last1'}";
eval('var obj='+string);
alert(obj.firstName);

输出

name1

我在几行代码中实现了一个相当可靠的解决方案。

有一个像这样的HTML元素，我想传递自定义选项:

<div class="my-element"
    data-options="background-color: #dadada; custom-key: custom-value;">
</div>

函数解析自定义选项并返回一个对象以在某处使用:

function readCustomOptions($elem){
    var i, len, option, options, optionsObject = {};

    options = $elem.data('options');
    options = (options || '').replace(/\s/g,'').split(';');
    for (i = 0, len = options.length - 1; i < len; i++){
        option = options[i].split(':');
        optionsObject[option[0]] = option[1];
    }
    return optionsObject;
}

console.log(readCustomOptions($('.my-element')));