In my mind I want to push a key-value on array.
Say for example in PHP this is done like this:
$err = array();
function check($k,$v) {
$err[$k] = $v;
}
How is this done exactly in JavaScript/jQuery?
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@FelixKling - any string send as parameterplanet x– planet x2012-05-07 08:50:39 +00:00Commented May 7, 2012 at 8:50
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2 Answers
Javascript key/value pair support in Object, not in Array
Insert Element:
var arr= [1,2,3],
result = {};
for(var key in arr) {
result[key] = arr[key]; // in this case key will be 0,1,2 i.e index of array element
}
Check that a key exists:
function checking(k, v) {
if(result.k != null || result.k != undefined) {
// do something
}
}
According to your function:
var err = {}; // not array, should be object
function check(k,v) {
err[k] = v; // or err.k = v;
}
More on insert:
var x = [];
x.some = 'some'; // OK; arrays are objects
x['some'] = 'some'; // exactly the same
Get value:
x.home; // give 'some'
x['home']; // give 'some'
Count length:
If you want to get length of an array you have to use .length.
For example:
x.length; // will return 1
And if you want to count the length of an Object:
var obj = {a: 'XYZ', b: 'PQR'};
Object.keys(obj).length; // will return 2
To Delete item:
if you want to remove an item from an Object:
delete obj[key];
to delete an item from an array:
delete arr[index]; // index is position of the element within array
also to remove array element you can do
arr.splice(0,2); // splice(index, howmany, [item1, item2, ...., itemx])
// in this example from start 2 items will delete
1 Comment
planet x
Gracias por esta. One more to ask, what is the equivalent of php count() in JS? I tested that .length doesn't fit in here.
You use an object. And do it in much the same way.
var $err = {};
function check($k, $v) {
$err[$k] = $v;
}
Granted, that's not an array though.
Do take note that you can actually do this in Javascript arrays, and the interpreter will let you.
var $err = []; // an array
function check($k, $v) {
$err[$k] = $v;
}
But you're not really pushing to the array, but rather extending the array object. You can check this out with this:
var foo = [];
foo['hello'] = 'world';
console.log(foo); // []
console.log(foo['hello']); // 'world'
console.log(foo.hello); // 'world'
console.log(foo.length); // 0
... so best to watch out for this gotcha. :D
4 Comments
Joseph
you can remove the
$ now. it's not required in JS :D
Richard Neil Ilagan
@Joseph ~ Yup, I know. But it adds to the dramatic, oh-my-gosh-so-similar effect! dun dun duuuuun! :D
planet x
@RichardNeilIlagan Gracias por esta. One more to ask, what is the equivalent of php
count() in JS? I tested that .length doesn't fit in here.Richard Neil Ilagan
For arrays, that just equates to
.length. For objects, that's a different beast altogether though. The same question has been asked here, so best to check the solutions posted there. stackoverflow.com/questions/126100/…