JS中的对象字符串

2020/10/18 05:41 · javascript ·  · 0评论

我有一个字符串

string = "firstName:name1, lastName:last1"; 

现在我需要一个对象obj这样

obj = {firstName:name1, lastName:last1}

如何在JS中做到这一点?

实际上,最好的解决方案是使用JSON:

文献资料

JSON.parse(text[, reviver]);

例子:

1)

var myobj = JSON.parse('{ "hello":"world" }');
alert(myobj.hello); // 'world'

2)

var myobj = JSON.parse(JSON.stringify({
    hello: "world"
});
alert(myobj.hello); // 'world'

3)将函数传递给JSON

var obj = {
    hello: "World",
    sayHello: (function() {
        console.log("I say Hello!");
    }).toString()
};
var myobj = JSON.parse(JSON.stringify(obj));
myobj.sayHello = new Function("return ("+myobj.sayHello+")")();
myobj.sayHello();

您的字符串看起来像没有花括号的JSON字符串。

然后应该可以工作:

obj = eval('({' + str + '})');

如果我正确理解:

var properties = string.split(', ');
var obj = {};
properties.forEach(function(property) {
    var tup = property.split(':');
    obj[tup[0]] = tup[1];
});

我假设属性名称在冒号的左边,而它所采用的字符串值在右边。

请注意,这Array.forEach是JavaScript 1.6-您可能希望使用工具包来获得最大的兼容性。

这个简单的方法

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

输出

name1

由于JSON.parse()方法要求将Object键括在引号中才能正常工作,因此在调用JSON.parse()方法之前,我们首先必须将字符串转换为JSON格式的字符串。

var obj = '{ firstName:"John", lastName:"Doe" }';

var jsonStr = obj.replace(/(\w+:)|(\w+ :)/g, function(matchedStr) {
  return '"' + matchedStr.substring(0, matchedStr.length - 1) + '":';
});

obj = JSON.parse(jsonStr); //converts to a regular object

console.log(obj.firstName); // expected output: John
console.log(obj.lastName); // expected output: Doe

即使该字符串具有复杂的对象(如以下对象),它也将起作用,并且仍然可以正确转换。只要确保字符串本身用单引号引起来即可。

var strObj = '{ name:"John Doe", age:33, favorites:{ sports:["hoops", "baseball"], movies:["star wars", "taxi driver"]  }}';

var jsonStr = strObj.replace(/(\w+:)|(\w+ :)/g, function(s) {
  return '"' + s.substring(0, s.length-1) + '":';
});

var obj = JSON.parse(jsonStr);
console.log(obj.favorites.movies[0]); // expected output: star wars

如果您使用的是JQuery:

var obj = jQuery.parseJSON('{"path":"/img/filename.jpg"}');
console.log(obj.path); // will print /img/filename.jpg

记住:评估是邪恶的!:D

您需要使用JSON.parse()将String转换为Object:

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

如果您有类似的字符串foo: 1, bar: 2,则可以使用以下命令将其转换为有效的obj:

str
  .split(',')
  .map(x => x.split(':').map(y => y.trim()))
  .reduce((a, x) => {
    a[x[0]] = x[1];
    return a;
  }, {});

感谢#javascript中的niggler。

更新说明:

const obj = 'foo: 1, bar: 2'
  .split(',') // split into ['foo: 1', 'bar: 2']
  .map(keyVal => { // go over each keyVal value in that array
    return keyVal
      .split(':') // split into ['foo', '1'] and on the next loop ['bar', '2']
      .map(_ => _.trim()) // loop over each value in each array and make sure it doesn't have trailing whitespace, the _ is irrelavent because i'm too lazy to think of a good var name for this
  })
  .reduce((accumulator, currentValue) => { // reduce() takes a func and a beginning object, we're making a fresh object
    accumulator[currentValue[0]] = currentValue[1]
    // accumulator starts at the beginning obj, in our case {}, and "accumulates" values to it
    // since reduce() works like map() in the sense it iterates over an array, and it can be chained upon things like map(),
    // first time through it would say "okay accumulator, accumulate currentValue[0] (which is 'foo') = currentValue[1] (which is '1')
    // so first time reduce runs, it starts with empty object {} and assigns {foo: '1'} to it
    // second time through, it "accumulates" {bar: '2'} to it. so now we have {foo: '1', bar: '2'}
    return accumulator
  }, {}) // when there are no more things in the array to iterate over, it returns the accumulated stuff

console.log(obj)

令人困惑的MDN文档:

演示:http : //jsbin.com/hiduhijevu/edit?js,console

功能:

const str2obj = str => {
  return str
    .split(',')
    .map(keyVal => {
      return keyVal
        .split(':')
        .map(_ => _.trim())
    })
    .reduce((accumulator, currentValue) => {
      accumulator[currentValue[0]] = currentValue[1]
      return accumulator
    }, {})
}

console.log(str2obj('foo: 1, bar: 2')) // see? works!

我用几行代码实现了一个可靠的解决方案。

有一个这样的HTML元素,我想在其中传递自定义选项:

<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该选项:

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')));
string = "firstName:name1, lastName:last1";

这将起作用:

var fields = string.split(', '),
    fieldObject = {};

if( typeof fields === 'object') ){
   fields.each(function(field) {
      var c = property.split(':');
      fieldObject[c[0]] = c[1];
   });
}

但是,效率不高。当您遇到如下情况时会发生什么:

string = "firstName:name1, lastName:last1, profileUrl:http://localhost/site/profile/1";

split()将拆分“ http”。所以我建议您使用特殊的分隔符,例如竖线

 string = "firstName|name1, lastName|last1";


   var fields = string.split(', '),
        fieldObject = {};

    if( typeof fields === 'object') ){
       fields.each(function(field) {
          var c = property.split('|');
          fieldObject[c[0]] = c[1];
       });
    }

我正在使用JSON5,并且效果很好。

好的部分是它包含no evalno new Function,使用非常安全。

这是通用代码,无论您输入的内容有多长,但如果存在:

var string = "firstName:name1, lastName:last1"; 
var pass = string.replace(',',':');
var arr = pass.split(':');
var empty = {};
arr.forEach(function(el,i){
  var b = i + 1, c = b/2, e = c.toString();
     if(e.indexOf('.') != -1 ) {
     empty[el] = arr[i+1];
  } 
}); 
  console.log(empty)

就你而言

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]);
}
var stringExample = "firstName:name1, lastName:last1 | firstName:name2, lastName:last2";    

var initial_arr_objects = stringExample.split("|");
    var objects =[];
    initial_arr_objects.map((e) => {
          var string = e;
          var fields = string.split(','),fieldObject = {};
        if( typeof fields === 'object') {
           fields.forEach(function(field) {
              var c = field.split(':');
              fieldObject[c[0]] = c[1]; //use parseInt if integer wanted
           });
        }
            console.log(fieldObject)
            objects.push(fieldObject);
        });

“对象”数组将具有所有对象

我知道这是一篇过时的文章,但是没有找到正确的答案。

var jsonStrig = '{';
      var items = string.split(',');
      for (var i = 0; i < items.length; i++) {
          var current = items[i].split(':');
          jsonStrig += '"' + current[0] + '":"' + current[1] + '",';
      }
      jsonStrig = jsonStrig.substr(0, jsonStrig.length - 1);
      jsonStrig += '}';
var obj = JSON.parse(jsonStrig);
console.log(obj.firstName, obj.lastName);

现在,您可以像使用对象一样正常使用obj.firstNameobj.lastName获取值。

这是我处理某些边缘情况的方法,例如将空格和其他原始类型作为值

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 };
  }, {});
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