Can someone tell me how to update the following code to just get the first item that's returned in an object (data)? I know using each() for just one item isn't very efficient and would like to improve it.
$(data).each(function(num, entry){
if ( num > 1 ) return false;
});
Here's an example of what data is:
[
{
"id": 1,
"title": "My post",
"permalink":"http:\/\/site.com\/page.html\/",
"date":" 2011-05-10
}
]
Update 2:
As data is just an array (I assume the JSON is already parsed (if not you can use jQuery.parseJSON or JSON.parse)), you can get the first element with simple array access:
var first = data[0];
Read more about arrays.
Old answer:
Try
$(data).first() // returns jQuery object
// or
$(data).eq(0) // returns jQuery object
// or
$(data).get(0) // returns DOM object
// or
$(data)[0] // returns DOM object
depending on the data you have and what you want to do.
Update:
If data is actually a JavaScript object, then there is no need to pass it to jQuery (jQuery is mostly for working with the DOM).
Just loop over it with
for(var prop in data) {
}
But you cannot get the "first" property because they are unordered.
If it is an array, just use data[0].
To help you more, you should post what data is.
You can do this:
$(data).get(0); //same as $(data)[0]
Related
JS noob here. I want to store a list of option for a dropdown in an array. I want a key to be associated with every value something like this
var newArray = [
{
key: "key",
val:({value:"val", label:"label"}, {value:"val",label:"label"})
}
]
The code above returns undefined when I try to read val. What is the solution? Thanks
var newArray = [
{
key: "key",
val:[{value:"val", label:"label"}, {value:"val",label:"label"}]
}]
The only thing i changed were parentheses () into [], because it's the thing that declares an array. Now, if you want to read the val key, you need to do this stuff.
You have an array named "newArray". It only has 1 element (which is also the first).
Now lets get the first element of the array by newArray[0]. Now you have accessed the object inside the array. Now you can read the the value by newArray[0].val. And now you have entered a new array, which elements you can read with newArray[0].val[0] and newArray[0].val[1]
I have an object with key value pairs inside an array:
var data = [
{
"errorCode":100,
"message":{},
"name":"InternetGatewayDevice.LANDevice.1.Hosts.HostNumberOfEntries",
"value":"2"
}
];
I want to get the value of "value" key in the object. ie, the output should be "2".
I tried this:
console.log(data[value]);
console.log(data.value);
Both logging "undefined". I saw similar questions in SO itself. But, I couldn't figure out a solution for my problem.
You can use the map property of the array. Never try to get the value by hardcoding the index value, as mentioned in the above answers, Which might get you in trouble. For your case the below code will works.
data.map(x => x.value)
You are trying to get the value from the first element of the array. ie, data[0]. This will work:
console.log(data[0].value);
If you have multiple elements in the array, use JavaScript map function or some other function like forEach to iterate through the arrays.
data.map(x => console.log(x.value));
data.forEach(x => console.log(x.value));
data is Array you need get first element in Array and then get Value property from Object,
var data = [{
"ErrorCode":100,
"Message":{},
"Name":"InternetGatewayDevice.LANDevice.1.Hosts.HostNumberOfEntries",
"Value":"2"
}];
console.log(data[0].Value);
Try this...
Actually Here Data is an array of object so you first need to access that object and then you can access Value of that object.
var data = [
{
"ErrorCode":100,
"Message":{},
"Name":"InternetGatewayDevice.LANDevice.1.Hosts.HostNumberOfEntries",
"Value":"2"
}
];
alert(data[0].Value);
what you are trying to read is an object which an element of an array, so you should first fetch the element of array by specifying its index like
data[0] and then read a property of the fetched object, i.e. .value,
so the complete syntax would be data[0].value
Hope it helps !
I have an array in javascript which looks like this:
var arr = [
{ // first
id : '45'
name : 'dsada'
},
{
id : '45'
name : 'dsada'
},
/* ... */
];
I want to add more data to the first index of it, e.g. country:'Egypt'.
Which function should I use?
Or how to push values to specific index in array?
I have used push and splice methods but I can't figure it out.
arr[0].country = 'Egypt'
Set the country property.
Scimonster's answer is correct, but it is better if you take a look to the documentation. Your question highlight some confusion on basics.
Documentation
The Array.prototype.push() method adds one or more elements to the end of an array and returns the new length of the array.
The Array.prototype.splice() method changes the content of an array, adding new elements while removing old elements.
The Object.prototype represents the Object prototype object.
I have an object that contains an array of objects from which I need to get a value of their properties.
As an example this is what I need to get:
Stronghold.bins.models[0].attributes.entity.title
Which returns "Stronghold Title 1"
function grabItemName(){
var itemName=$(Stronghold.bins).each(function(){
return this.models[0].attributes.entity.title == title;
console.log(itemName);
})
};
(if there is a better way for me to ask this question please let me know)
I apologize if this was poorly asked!
The current issue is that it does not understand the array value '[0]' and cannot read it as it is undefined. What do I need to do to grab the 'title' value of all items in the array?
What do I need to do to grab the 'title' value of all items in the array?
That's what .map [docs] is for. It lets you map each value in an array to another value.
In the following I assume you want to iterate over each Stronghold.bins.models, because iterating over Stronghold.bins does not make sense with the provided information:
var titles = $.map(Stronghold.bins.models, function(obj) {
return obj.attributes.entity.title;
});
// `titles` is now an array containing `.attributes.entity.title;` of
// each object.
The current issue is that it does not understand the array value '[0]' and cannot read it as it is undefined.
Well, that won't happend anymore ;) In your example you where iterating over the properties of the Stronghold.bins object. One of these properties is models itself (!) and I doubt that any other property value has a models property.
Try using the other version of the each function:
$.each(Stronghold.bins, function () {
});
The version you are using is for looping through an element on the page, e.g $('body div p').each(function() {}), which isn't what you want in this instance: You want to loop over the values contained in Stronghold.bins.
I'm having trouble deleting/removing an item from an Array in jQuery. I've run the results in console.log() and it shows up as an Object. I've created a function which returns a json string and then I parses it, an example below:
var ret = jQuery.parseJSON($.return_json(data));
It works nicely, however, I am running an $.each loop which removes items from that array/object.
var old = $("element").find("li[rel=item]");
$.each(old, function(index, value) {
ret.splice($(value).attr("id"), 1);
});
Above, I am searching for elements with attribute rel = item. The same element contains an id which is related to the index of the function which returns the json parsed variable.
I ran Developers Tools in Google Chrome to see the error and it prints:
Uncaught TypeError: Object #<Object> has no method 'splice'
Any words of guidance will be much appreciated. Thanks.
It seems like ret is not actually an array (and likely an object (ex: {someName: "someVal"}) instead).
I'm also making an assumption that you mean for $(value).attr("id") to be a string identifier like someName in the object example above. If that is the case and you are working with an object and you do have the appropriate property identifier, then luckily there is an easier solve than splice.
Try:
$("element").find("li[rel=item]").each(function() {
delete ret[$(this).attr("id")];
});
splice is only a method of arrays, not objects. ret in this case, is an object, not an array.
If you are trying to remove specific elements from an object, you can do this:
$("element").find("li[rel=item]").each(function(i,v){
delete ret[v.id];
});
ps. You can use .each instead of $.each.
If you really want to make the object into an array, you can simply loop through it and push the elements into an array.
var obj = {"1":"item 1", "2": "item 2", "3": "Item 3"};
var arr = [];
for(i in obj){
if(obj.hasOwnProperty(i)){
arr.push(obj[i]);
}
}
ret is the JSON object containing the array, and you can't splice it. You need to reference whatever you called the array within the object and splice that.
(Would help if you posted the code where you define the array).