jQuery 每个循环 3 维对象数组答案

【问题标题】：jQuery each loop 3-Dimensional Object ArrayjQuery 每个循环 3 维对象数组
【发布时间】：2016-10-24 16:37:45
【问题描述】：

我有一个要循环的多维数组。我希望循环最终查看第一个对象（在示例代码中为："pressure"），然后对第一个对象内的每个对象执行特定操作。

但我什至无法让它正常工作。我知道我的$.each 函数完全错误 — 我只是不知道如何使它正确。当然，我在控制台中什么也得不到。

$(document).ready(function() {
  var units = {
    "pressure": [
      {
        short: "atm",
        val: "1",
        long: "Atmosphere (standard)"
      }, {
        short: "bar",
        val: "1.01325027383089",
        long: "Bar"
      }, {
        short: "cmHg",
        val: "76.0000526890144",
        long: "Centimeter of Mercury (0&#8451;)"
      }, {
        short: "cmH2O",
        val: "1033.25183423631",
        long: "Centimeter of Water (4&#8451;)"
      }, {
        short: "ft-H2O",
        val: "33.899503811341",
        long: "Foot of Water (4&#8451;)"
      }, {
        short: "GPa",
        val: "0.00010132502738",
        long: "Gigapascal"
      }, {
        short: "HPa",
        val: "1013.25027383088",
        long: "Hectopascal"
      }, {
        short: "inHg",
        val: "29.9212805862261",
        long: "Inch of Mercury (0&#8451;)"
      }, {
        short: "inH2O",
        val: "406.793640435982",
        long: "Inch of Water (4&#8451;)"
      }, {
        short: "kPa",
        val: "101.325027383089",
        long: "Kilopascal"
      }, {
        short: "MPa",
        val: "0.10132502738309",
        long: "MegaPascal"
      }, {
        short: "mbar",
        val: "1013.25027383088",
        long: "Millibar"
      }, {
        short: "mtorr",
        val: "760000.526890144",
        long: "Millitorr"
      }, {
        short: "mmHg",
        val: "760.000205385833",
        long: "Millimeter of Mercury (0&#8451;)"
      }, {
        short: "mmH2O",
        val: "10332.5183423631",
        long: "Millimeter of Water (4&#8451;)"
      }, {
        short: "Pa",
        val: "101325.027383088",
        long: "Pascal"
      }, {
        short: "psf",
        val: "2116.21372690676",
        long: "Pound-Force/Square-Foot"
      }, {
        short: "psi",
        val: "14.6959793215884",
        long: "Pound-Force/Square-Inch"
      }, {
        short: "Torr",
        val: "760.000526890144",
        long: "Torr"
      }
    ],

    "density": [

      {
        short: "lb/in3",
        val: "1",
        long: "Pound / Inch-Cubed"
      }, {
        short: "lb/ft3",
        val: "1728.00001173627",
        long: "Pound / Foot-Cubed"
      }, {
        short: "slug/ft3",
        val: "53.707964051111",
        long: "Slug / Foot-Cubed"
      }, {
        short: "grain/ft3",
        val: "12094392.8271733",
        long: "Grain / Foot-Cubed"
      }, {
        short: "grain/in3",
        val: "6999.99988928036",
        long: "Grain / Inch-Cubed"
      }, {
        short: "g/cm3",
        val: "27.679904710267",
        long: "Gram / Centimeter-Cubed"
      }, {
        short: "g/cup",
        val: "6.548788655679",
        long: "Gram / Cup"
      }, {
        short: "g/L",
        val: "27679.9047102671",
        long: "Gram / Liter"
      }, {
        short: "kg/cm3",
        val: "0.02767990471",
        long: "Kilogram / Centimeter-Cubed"
      }, {
        short: "kg/L",
        val: "27.679904710267",
        long: "Kilogram / Liter"
      }, {
        short: "kg/m3",
        val: "27679.9047102671",
        long: "Kilogram / Meter-Cubed"
      }
    ]
  };

  $.each(units, function(index, obj) {
    $.each(obj, function(short, val) {
      console.log(obj.index.short);
      console.log(obj.index.val);
    });
  });

});

&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;

【问题讨论】：

在您的情况下，您可能希望使用一些 for(var type in units){ for(var property in units[type]){ } } 进行迭代
obj.index?你不是说obj[index]吗？
只需使用纯 javascript for..in..
Javascript iterate object的可能重复
@ShaunakD：jQuery 的 $.each 对对象和数组都有效。

标签： javascript jquery multidimensional-array foreach

【解决方案1】：

你可能想做这样的事情：

Object.keys(units).forEach((key, index) => { // loop over the units keys
    units[key].forEach(object => { // loop over the objects in arrays
        // do your stuff with the objects
    });
});

【讨论】：

【解决方案2】：

$.each(units, function(index, obj) {
console.log(index)
  $.each(obj, function(short, val ) {
    console.log(val.short);
    console.log(val.val);
  });
});

【讨论】：

你离得很近。 Rocket Hazmat 只快了 1 分钟。

【解决方案3】：

当您使用 . 语法来引用对象属性时，您正在尝试访问该 literal 属性。

例如，obj.index.short。这会查找名为index 的属性，然后查找名为short 的属性。我假设您希望使用 index 变量，以便您访问正确的属性。

类似：obj[index].short。这也不起作用，因为您的 obj[index] 值是一个数组。

你要做的是循环外部对象，然后循环每个属性（这是一个数组）并获取每个数组元素（对象）的值。

试试这个：

$.each(units, function(index, obj){
    // `index` is either "pressure" or "density"
    // `obj` is the value of that property (an array)
    $.each(obj, function(short, val){
        // `short` is the index in the array
        // `val` is each element in the array, it's an object
        console.log(val.short);
        console.log(val.val);
    });
});

【讨论】：

谢谢！这很好用。我想我不应该使用“val”作为键
@Sanya：我猜你没有val.val，这可能看起来很傻。您可以将 val 保留为对象中的属性，只需更改代码以使用其他内容，例如 data.val 或其他内容。

【解决方案4】：

$(document).ready(function() {
  var units = {
    "pressure": [
      {
        short: "atm",
        val: "1",
        long: "Atmosphere (standard)"
      }, {
        short: "bar",
        val: "1.01325027383089",
        long: "Bar"
      }, {
        short: "cmHg",
        val: "76.0000526890144",
        long: "Centimeter of Mercury (0&#8451;)"
      }, {
        short: "cmH2O",
        val: "1033.25183423631",
        long: "Centimeter of Water (4&#8451;)"
      }, {
        short: "ft-H2O",
        val: "33.899503811341",
        long: "Foot of Water (4&#8451;)"
      }, {
        short: "GPa",
        val: "0.00010132502738",
        long: "Gigapascal"
      }, {
        short: "HPa",
        val: "1013.25027383088",
        long: "Hectopascal"
      }, {
        short: "inHg",
        val: "29.9212805862261",
        long: "Inch of Mercury (0&#8451;)"
      }, {
        short: "inH2O",
        val: "406.793640435982",
        long: "Inch of Water (4&#8451;)"
      }, {
        short: "kPa",
        val: "101.325027383089",
        long: "Kilopascal"
      }, {
        short: "MPa",
        val: "0.10132502738309",
        long: "MegaPascal"
      }, {
        short: "mbar",
        val: "1013.25027383088",
        long: "Millibar"
      }, {
        short: "mtorr",
        val: "760000.526890144",
        long: "Millitorr"
      }, {
        short: "mmHg",
        val: "760.000205385833",
        long: "Millimeter of Mercury (0&#8451;)"
      }, {
        short: "mmH2O",
        val: "10332.5183423631",
        long: "Millimeter of Water (4&#8451;)"
      }, {
        short: "Pa",
        val: "101325.027383088",
        long: "Pascal"
      }, {
        short: "psf",
        val: "2116.21372690676",
        long: "Pound-Force/Square-Foot"
      }, {
        short: "psi",
        val: "14.6959793215884",
        long: "Pound-Force/Square-Inch"
      }, {
        short: "Torr",
        val: "760.000526890144",
        long: "Torr"
      }
    ],

    "density": [

      {
        short: "lb/in3",
        val: "1",
        long: "Pound / Inch-Cubed"
      }, {
        short: "lb/ft3",
        val: "1728.00001173627",
        long: "Pound / Foot-Cubed"
      }, {
        short: "slug/ft3",
        val: "53.707964051111",
        long: "Slug / Foot-Cubed"
      }, {
        short: "grain/ft3",
        val: "12094392.8271733",
        long: "Grain / Foot-Cubed"
      }, {
        short: "grain/in3",
        val: "6999.99988928036",
        long: "Grain / Inch-Cubed"
      }, {
        short: "g/cm3",
        val: "27.679904710267",
        long: "Gram / Centimeter-Cubed"
      }, {
        short: "g/cup",
        val: "6.548788655679",
        long: "Gram / Cup"
      }, {
        short: "g/L",
        val: "27679.9047102671",
        long: "Gram / Liter"
      }, {
        short: "kg/cm3",
        val: "0.02767990471",
        long: "Kilogram / Centimeter-Cubed"
      }, {
        short: "kg/L",
        val: "27.679904710267",
        long: "Kilogram / Liter"
      }, {
        short: "kg/m3",
        val: "27679.9047102671",
        long: "Kilogram / Meter-Cubed"
      }
    ]
  };

  $.each(units, function(i, obj) {     
      console.log(i);
     $.each(obj, function(j, obj2) {
         console.log(obj2.short +' : '+obj2.val+' , '+obj2.long);
     });
    
  });

});

&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;

【讨论】：

【解决方案5】：

单位是一个对象，压力是这个对象的关键

var _getPressure=units.pressure // will return value of key pressure
 _getPressure.forEach(function(item){ // use Array forEach to loop through array
 document.write('<pre>'+item.short+'--'+item.val+'</pre>')
 })

JSFIDDLE

【讨论】：