blocks|key|5573235|text|尝试从外部对象迭代并打印它，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5573236|data.forEach(function(country){+//For+the+countries
++country.state.forEach(state){+//For+the+states
++++console.log(state.state_code,state.state_description);
++});
});|code-block|syntax|javascript|5573237|需要注意的是，在迭代数组时不应该使用for-in循环。因为它将遍历整个prototypes中对象的所有enumerable属性。我看到你在使用.hasOwnProperty()，这将有助于避免这种情况，但在我们的例子中，使用for-in循环是不必要的。|offset|length|style|CODE|5573238|DEMO|5573239|entityMap|0|LINK|mutability|MUTABLE|url|https://jsfiddle.net/hp6vj1sk/^0|0|0|I|6|Z|A|1F|A|1Z|H|0|0|4|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]|$I|11|J|12|K|L]|$I|13|J|14|K|L]|$I|15|J|16|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|17|8|@]|9|@$I|18|J|19|1|1A]]|A|$]]|$1|O|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

Try to iterate from the outer object and print it,

<pre><code>data.forEach(function(country){ //For the countries
 country.state.forEach(state){ //For the states
 console.log(state.state_code,state.state_description);
 });
});
</code></pre>

As a side note, You should not use <code>for-in</code> loop while iterating over an array. Since it will iterate over all the <code>enumerable</code> properties of an object throughout the <code>prototypes</code>. I saw you using <code>.hasOwnProperty()</code>, that would help avoid such situations, but in our case, using for-in loop is unnecessary.

<h2><a href="https://jsfiddle.net/hp6vj1sk/" rel="nofollow">DEMO</a></h2>

blocks|key|1495773|text|如果您希望每个state_code都有一个数组：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1495774|var+result+=+data.reduce(function(ar,+d)+{
++++//+iterate+over+the+state+array+of+each+item
++++d.state.forEach(function(s){
++++++//+push+the+state_code+property+to+our+resulting+array
++++++//+you+could+add+a+condition+such+as+
++++++//+if(s.state_code+===+"AD1")+ar.push(s.state_code)
++++++ar.push(s.state_code)
++++});
++++return+ar;
},+[])|code-block|syntax|javascript|1495775|请参阅fiddle|offset|length|1495776|entityMap|0|LINK|mutability|MUTABLE|url|https://jsfiddle.net/oxLgamdr/1/^0|0|0|3|6|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

If you want an array with every state_code:

<pre><code>var result = data.reduce(function(ar, d) {
 // iterate over the state array of each item
 d.state.forEach(function(s){
 // push the state_code property to our resulting array
 // you could add a condition such as 
 // if(s.state_code === "AD1") ar.push(s.state_code)
 ar.push(s.state_code)
 });
 return ar;
}, [])
</code></pre>

See <a href="https://jsfiddle.net/oxLgamdr/1/" rel="nofollow">fiddle</a>

blocks|key|1787714|text|试试这段代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1787715|for+(var+i+=+0;+i+<+data.length;+i%2B%2B)+{
++++for+(var+j+=+0;+j+<+data[i].state.length;+j%2B%2B)+{
++++++++if(data[i].state[j].state_code+===+"AD1"){
++++++++++++console.log(data[i].state[j].state_description)
++++++++}
++++};
};|code-block|syntax|javascript|1787716|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

try this code

<pre><code>for (var i = 0; i &lt; data.length; i++) {
 for (var j = 0; j &lt; data[i].state.length; j++) {
 if(data[i].state[j].state_code === "AD1"){
 console.log(data[i].state[j].state_description)
 }
 };
};
</code></pre>

blocks|key|5573285|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5573286|data.forEach(function(obj){
++
+var+states+=+obj.state;
+if(Array.isArray(states)){
+++
+++states.forEach(function(state){
+++++if(state.state_code+===+"AD1"){
++++++console.log(state.state_description);
+++++}
+++});
+}+else+{
+++if(states.state_code+===+"AD1"){
++++++console.log(states.state_description);
+++}
+}
++
});|code-block|syntax|javascript|5573287|5573288|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|K|8|@]|9|@]|A|$E|F]]|$1|G|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|M|8|@]|9|@]|A|$]]]|I|$]]

<div class="snippet" data-lang="js" data-hide="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>data.forEach(function(obj){
 
 var states = obj.state;
 if(Array.isArray(states)){
 
 states.forEach(function(state){
 if(state.state_code === "AD1"){
 console.log(state.state_description);
 }
 });
 } else {
 if(states.state_code === "AD1"){
 console.log(states.state_description);
 }
 }
 
});</code></pre>
</div>
</div>

blocks|key|1495800|text|for...in语句遍历对象的可枚举属性|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|BOLD|entityRanges|data|1495801|对于迭代循环，请使用for+Arrays或Array#forEach函数|1495802|for+(var+i+=+0;+i+<+data.length;+i%2B%2B)+{
++++for+(var+j+=+0;+j+<+data[i].state.length;+j%2B%2B)+{
++++++++if+(data[i].state[j].state_code+===+"AD1")+{
++++++++++++console.log(data[i].state[j].state_description);
++++++++}
++++}
}|code-block|syntax|javascript|1495803|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for|1|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach^0|0|8|C|2|0|E|6|A|3|0|L|D|1|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|D]]|E|@]|F|$]]|$1|G|3|H|5|6|7|12|8|@$9|13|A|14|B|C]]|E|@$9|15|A|16|1|17]|$9|18|A|19|1|1A]]|F|$]]|$1|I|3|J|5|K|7|1B|8|@]|E|@]|F|$L|M]]|$1|N|3|-4|5|6|7|1C|8|@]|E|@]|F|$]]]|O|$P|$5|Q|R|S|F|$T|U]]|V|$5|Q|R|S|F|$T|W]]]]

The <code>for...in</code> statement iterates over the enumerable properties of an object

For iterating <code>Arrays</code> use <a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/for" rel="nofollow">for</a> loop or <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach" rel="nofollow">Array#forEach</a> function

<pre><code>for (var i = 0; i &lt; data.length; i++) {
 for (var j = 0; j &lt; data[i].state.length; j++) {
 if (data[i].state[j].state_code === "AD1") {
 console.log(data[i].state[j].state_description);
 }
 }
}
</code></pre>

blocks|key|5573337|text|声明数据变量是一个对象数组。其中每个对象都包含一个状态数组。因此，如果你想迭代到深度，循环应该是这样的(它工作得很好，我已经测试过了)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5573338|++++for+(var+i+=+0;+i+<=+data.length;+i%2B%2B)+{
++++++++for(var+j+=+0;+j+<=+data[i].state.length;+j%2B%2B){
++++++++++++alert("The+code+is+::"+%2B+data[i].state[j].state_code);
++++++++}
++++}|code-block|syntax|javascript|5573339|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Your declare data variable is an array of object. Where each object contains an array of state in it. Hence, if you want to iterate into deep, loop should be something like this (it is working fine, i have tested).

<pre><code> for (var i = 0; i &lt;= data.length; i++) {
 for(var j = 0; j &lt;= data[i].state.length; j++){
 alert("The code is ::" + data[i].state[j].state_code);
 }
 }
</code></pre>

I have a json like :

<pre><code>var data = [
 {
 "country":"Andorra",
 "code":"AD",
 "state":[
 {
 "state_code":"AD1",
 "state_description":"aaAndorra1"
 },
 {
 "state_code":"AD2",
 "state_description":"aaAndorra2"
 }
 ]
 }
]
</code></pre>

I would like to loop though the state property and get the state_code value

This is how I'm doing it :

<pre><code>for (var key in data) {
 if (data.hasOwnProperty(key)) {
 if(data[key].state.state_code === "AD1"){
 console.log(data[key].state.state_description);
 }
 }
</code></pre>

I'm getting undefined.

Any help please?

Thanks

Read complex JSON in Javascript

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个像这样的json：var data = [   {      "country":"Andorra",      "code":"AD",      "state":[         {            "state_code":"AD1",            "state_description"...

问在Javascript中读取复杂的JSON
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