我有一个这样的数据结构:
var someObject = {
'part1' : {
'name': 'Part 1',
'size': '20',
'qty' : '50'
},
'part2' : {
'name': 'Part 2',
'size': '15',
'qty' : '60'
},
'part3' : [
{
'name': 'Part 3A',
'size': '10',
'qty' : '20'
}, {
'name': 'Part 3B',
'size': '5',
'qty' : '20'
}, {
'name': 'Part 3C',
'size': '7.5',
'qty' : '20'
}
]
};
我想使用这些变量访问数据:
var part1name = "part1.name";
var part2quantity = "part2.qty";
var part3name1 = "part3[0].name";
part1name应该用someObject.part1.name的值填充，即“Part 1”。part2quantity也是一样，它的容量是60。
有没有办法实现这与纯javascript或JQuery?
最近遇到了同样的问题，并且成功地使用了https://npmjs.org/package/tea-properties，它也设置了嵌套对象/数组:
get:
var o = {
prop: {
arr: [
{foo: 'bar'}
]
}
};
var properties = require('tea-properties');
var value = properties.get(o, 'prop.arr[0].foo');
assert(value, 'bar'); // true
set:
var o = {};
var properties = require('tea-properties');
properties.set(o, 'prop.arr[0].foo', 'bar');
assert(o.prop.arr[0].foo, 'bar'); // true
AngularJS有$scope.$eval
在AngularJS中，我们可以使用$scope。$eval方法访问嵌套对象:
$scope.someObject = someObject;
console.log( $scope.$eval("someObject.part3[0].name") ); //Part 3A
有关更多信息，请参见
AngularJS $scope API引用- $eval
演示
angular.module("app",[])
.run(function($rootScope) {
$rootScope.someObject = {
'part2' : {
'name': 'Part 2',
'size': '15',
'qty' : '60'
},
'part3' : [{
'name': 'Part 3A',
'size': '10',
'qty' : '20'
},{
name: 'Part 3B'
}]
};
console.log(
"part3[0].name =",
$rootScope.$eval("someObject.part3[0].name")
);
})
<script src="//unpkg.com/angular/angular.js"></script>
<body ng-app="app"
</body>
也适用于对象内的数组/数组。
防御无效值。
/**
* Retrieve nested item from object/array
* @param {Object|Array} obj
* @param {String} path dot separated
* @param {*} def default value ( if result undefined )
* @returns {*}
*/
function path(obj, path, def){
var i, len;
for(i = 0,path = path.split('.'), len = path.length; i < len; i++){
if(!obj || typeof obj !== 'object') return def;
obj = obj[path[i]];
}
if(obj === undefined) return def;
return obj;
}
//////////////////////////
// TEST //
//////////////////////////
var arr = [true, {'sp ace': true}, true]
var obj = {
'sp ace': true,
arr: arr,
nested: {'dotted.str.ing': true},
arr3: arr
}
shouldThrow(`path(obj, "arr.0")`);
shouldBeDefined(`path(obj, "arr[0]")`);
shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);
shouldBeTrue(`path(obj, "sp ace")`);
shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");
shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);
<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>
mohamed Hamouday' Answer的扩展将填补缺失的关键
function Object_Manager(obj, Path, value, Action, strict)
{
try
{
if(Array.isArray(Path) == false)
{
Path = [Path];
}
let level = 0;
var Return_Value;
Path.reduce((a, b)=>{
console.log(level,':',a, '|||',b)
if (!strict){
if (!(b in a)) a[b] = {}
}
level++;
if (level === Path.length)
{
if(Action === 'Set')
{
a[b] = value;
return value;
}
else if(Action === 'Get')
{
Return_Value = a[b];
}
else if(Action === 'Unset')
{
delete a[b];
}
}
else
{
return a[b];
}
}, obj);
return Return_Value;
}
catch(err)
{
console.error(err);
return obj;
}
}
例子
obja = {
"a": {
"b":"nom"
}
}
// Set
path = "c.b" // Path does not exist
Object_Manager(obja,path.split('.'), 'test_new_val', 'Set', false);
// Expected Output: Object { a: Object { b: "nom" }, c: Object { b: "test_new_value" } }
