在不知道JavaScript对象的键的情况下,我如何将…

var obj = {
   param1: 'something',
   param2: 'somethingelse',
   param3: 'another'
}

obj[param4] = 'yetanother';

…到…

var str = 'param1=something&param2=somethingelse&param3=another&param4=yetanother';

...?


当前回答

如果你需要一个递归函数来根据给定的对象生成正确的URL参数,试试我的Coffee-Script。

@toParams = (params) ->
    pairs = []
    do proc = (object=params, prefix=null) ->
      for own key, value of object
        if value instanceof Array
          for el, i in value
            proc(el, if prefix? then "#{prefix}[#{key}][]" else "#{key}[]")
        else if value instanceof Object
          if prefix?
            prefix += "[#{key}]"
          else
            prefix = key
          proc(value, prefix)
        else
          pairs.push(if prefix? then "#{prefix}[#{key}]=#{value}" else "#{key}=#{value}")
    pairs.join('&')

或者JavaScript编译…

toParams = function(params) {
  var pairs, proc;
  pairs = [];
  (proc = function(object, prefix) {
    var el, i, key, value, _results;
    if (object == null) object = params;
    if (prefix == null) prefix = null;
    _results = [];
    for (key in object) {
      if (!__hasProp.call(object, key)) continue;
      value = object[key];
      if (value instanceof Array) {
        _results.push((function() {
          var _len, _results2;
          _results2 = [];
          for (i = 0, _len = value.length; i < _len; i++) {
            el = value[i];
            _results2.push(proc(el, prefix != null ? "" + prefix + "[" + key + "][]" : "" + key + "[]"));
          }
          return _results2;
        })());
      } else if (value instanceof Object) {
        if (prefix != null) {
          prefix += "[" + key + "]";
        } else {
          prefix = key;
        }
        _results.push(proc(value, prefix));
      } else {
        _results.push(pairs.push(prefix != null ? "" + prefix + "[" + key + "]=" + value : "" + key + "=" + value));
      }
    }
    return _results;
  })();
  return pairs.join('&');
};

这将构造如下的字符串:

toParams({a: 'one', b: 'two', c: {x: 'eight', y: ['g','h','j'], z: {asdf: 'fdsa'}}})

"a=one&b=two&c[x]=eight&c[y][0]=g&c[y][1]=h&c[y][2]=j&c[y][z][asdf]=fdsa"

其他回答

如果你需要一个递归函数来根据给定的对象生成正确的URL参数,试试我的Coffee-Script。

@toParams = (params) ->
    pairs = []
    do proc = (object=params, prefix=null) ->
      for own key, value of object
        if value instanceof Array
          for el, i in value
            proc(el, if prefix? then "#{prefix}[#{key}][]" else "#{key}[]")
        else if value instanceof Object
          if prefix?
            prefix += "[#{key}]"
          else
            prefix = key
          proc(value, prefix)
        else
          pairs.push(if prefix? then "#{prefix}[#{key}]=#{value}" else "#{key}=#{value}")
    pairs.join('&')

或者JavaScript编译…

toParams = function(params) {
  var pairs, proc;
  pairs = [];
  (proc = function(object, prefix) {
    var el, i, key, value, _results;
    if (object == null) object = params;
    if (prefix == null) prefix = null;
    _results = [];
    for (key in object) {
      if (!__hasProp.call(object, key)) continue;
      value = object[key];
      if (value instanceof Array) {
        _results.push((function() {
          var _len, _results2;
          _results2 = [];
          for (i = 0, _len = value.length; i < _len; i++) {
            el = value[i];
            _results2.push(proc(el, prefix != null ? "" + prefix + "[" + key + "][]" : "" + key + "[]"));
          }
          return _results2;
        })());
      } else if (value instanceof Object) {
        if (prefix != null) {
          prefix += "[" + key + "]";
        } else {
          prefix = key;
        }
        _results.push(proc(value, prefix));
      } else {
        _results.push(pairs.push(prefix != null ? "" + prefix + "[" + key + "]=" + value : "" + key + "=" + value));
      }
    }
    return _results;
  })();
  return pairs.join('&');
};

这将构造如下的字符串:

toParams({a: 'one', b: 'two', c: {x: 'eight', y: ['g','h','j'], z: {asdf: 'fdsa'}}})

"a=one&b=two&c[x]=eight&c[y][0]=g&c[y][1]=h&c[y][2]=j&c[y][z][asdf]=fdsa"

由于我对递归函数做了这么大的研究,下面是我自己的版本。

function objectParametize(obj, delimeter, q) {
    var str = new Array();
    if (!delimeter) delimeter = '&';
    for (var key in obj) {
        switch (typeof obj[key]) {
            case 'string':
            case 'number':
                str[str.length] = key + '=' + obj[key];
            break;
            case 'object':
                str[str.length] = objectParametize(obj[key], delimeter);
        }
    }
    return (q === true ? '?' : '') + str.join(delimeter);
}

http://jsfiddle.net/userdude/Kk3Lz/2/

一个有用的代码,当你有数组在你的查询:

var queryString = Object.keys(query).map(key => {
    if (query[key].constructor === Array) {
        var theArrSerialized = ''
        for (let singleArrIndex of query[key]) {
            theArrSerialized = theArrSerialized + key + '[]=' + singleArrIndex + '&'
        }
        return theArrSerialized
    }
    else {
        return key + '=' + query[key] + '&'
    }
}
).join('');
console.log('?' + queryString)
var str = '';

for( var name in obj ) {
    str += (name + '=' + obj[name] + '&');
}

str = str.slice(0,-1);

试试吧。

例如:http://jsfiddle.net/T2UWT/

一个优雅的例子:(假设你正在运行一个现代的浏览器或节点)

var str = Object.keys(obj).map(function(key) {
  return key + '=' + obj[key];
}).join('&');

以及ES2017的等效版本:(感谢Lukas)

let str = Object.entries(obj).map(([key, val]) => `${key}=${val}`).join('&');

注意:如果键/值不是URL编码的,则可能需要使用encodeURIComponent()。