我在使用嵌套的$ .each循环访问对象时遇到问题。该对象是一系列嵌套在rootObject下的相同类型/类的对象。
对象
var rootObject ={};
rootObject.reportObject1.name = "reportObject1 Name";
rootObject.reportObject1.prop1 = "reportObject1 Prop1_Value";
rootObject.reportObject1.prop2 = "reportObject1 Prop2_Value";
rootObject.reportObject1.reportObjectA.name = "reportObjectA Name";
rootObject.reportObject1.reportObjectA.prop1 = "reportObjectA Prop1_Value";
rootObject.reportObject1.reportObjectA.prop2 = "reportObjectA Prop2_Value";
循环
$.each(rootObject, function(index0, value0){
console.log(value0.name);
$.each(value0, function(index1, value1){
console.log(value1.name);
}
}
问题
value1.name
返回循环中名称以外的对象属性。它似乎试图返回prop1
&的value.name。 prop2
,导致“未定义”值。
在调试期间查看value0
的值时,value0
在进入嵌套循环时似乎会丢失其值。来自父循环的console.log(value1.name)
,value0
变为undefined
;
在调试过程中查看子循环(index1, value1
)时,我发现value1
现在等于value0.name
,而index1
等于“name”。
答案 0 :(得分:2)
您可以自动定义一个级别的属性,但是对于两个属性,您需要停止并实例化父级:
var rootObject ={};
rootObject.reportObject1 = {}; // HERE
rootObject.reportObject1.name = "reportObject1 Name";
rootObject.reportObject1.prop1 = "reportObject1 Prop1_Value";
rootObject.reportObject1.prop2 = "reportObject1 Prop2_Value";
rootObject.reportObject1.reportObjectA = {}; // and HERE
rootObject.reportObject1.reportObjectA.name = "reportObjectA Name";
rootObject.reportObject1.reportObjectA.prop1 = "reportObjectA Prop1_Value";
rootObject.reportObject1.reportObjectA.prop2 = "reportObjectA Prop2_Value";
如果没有这些,这些属性实际上都没有定义,导致您的undefined
结果。
下一个问题是另一个语法问题:您在两个$.each()
来电时错过了右括号:
$.each(rootObject, function(index0, value0){
console.log(value0.name);
$.each(value0, function(index1, value1){
console.log(value1.name);
}); // HERE
}); // and HERE
通过这两个修复程序,您的控制台输出显示:
reportObject1 Name
undefined (x3)
reportObjectA Name
要获得正确的输出或至少一些样本输出,您可以使用这个小宝石(from here)。因为你的结构可能有两个以上的级别,所以递归似乎是合适的。
function enumerate(o,s){
//if s isn't defined, set it to an empty string
s = typeof s !== 'undefined' ? s : "";
//iterate across o, passing keys as k and values as v
$.each(o, function(k,v){
//if v has nested depth
if(typeof v == "object"){
//write the key to the console
console.log(s+k+": ");
//recursively call enumerate on the nested properties
enumerate(v,s+" ");
} else {
//log the key & value
console.log(s+k+": "+String(v));
}
});
}
如果您尝试enumerate(rootObject)
,您将获得:
reportObject1:
name: reportObject1 Name
prop1: reportObject1 Prop1_Value
prop2: reportObject1 Prop2_Value
reportObjectA:
name: reportObjectA Name
prop1: reportObjectA Prop1_Value
prop2: reportObjectA Prop2_Value