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How to check 'undefined' value in jQuery
...
when I am testing "typeof obj === undefined", the alert(typeof obj) returning object, even though obj is undefined.
Since obj is type of Object its returning Object, not undefined.
So after hours of testing I opted below technique.
if(document.getElementById(obj) !== null)...
How do I test for an empty JavaScript object?
...onsider: Object.prototype.a='hi'; var obj={}; alert(obj.a); // outputs "hi" isEmpty(obj) // returns false
– venimus
Apr 8 '11 at 14:38
30
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How to use OR condition in a JavaScript IF statement?
...xpressions, too:
var thingToTest = "B";
if (/A|B/.test(thingToTest)) alert("Do something!")
Here's an example of regular expressions in general:
var myString = "This is my search subject"
if (/my/.test(myString)) alert("Do something here!")
This will look for "my" within th...
Invoking a jQuery function after .each() has completed
...t(200, function() {
$(elm).remove();
});
}).promise().done( function(){ alert("All was done"); } );
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Variable name as a string in Javascript
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var x = 2;
for(o in window){
if(window[o] === x){
alert(o);
}
}
However, I think you should do like "karim79"
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foll...
Accessing JSON object keys having spaces [duplicate]
...ion.
var test = {
"id": "109",
"No. of interfaces": "4"
}
alert(test["No. of interfaces"]);
For more info read out here:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects
...
How to make input type= file Should accept only pdf and xls
...rget.files[0];
if(file.size>=2*1024*1024) {
alert("JPG images of maximum 2MB");
$("#form-id").get(0).reset(); //the tricky part is to "empty" the input file here I reset the form.
return;
}
if(!file.type.match('i...
What is the preferred syntax for defining enums in JavaScript?
...Script anymore. See my blog post for more details: Enums in JavaScript.
Alerting the name is already possible:
if (currentColor == my.namespace.ColorEnum.RED) {
// alert name of currentColor (RED: 0)
var col = my.namespace.ColorEnum;
for (var name in col) {
if (col[name] == col.RED...
How to delete last character from a string using jQuery?
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Why use jQuery for this?
str = "123-4";
alert(str.substring(0,str.length - 1));
Of course if you must:
Substr w/ jQuery:
//example test element
$(document.createElement('div'))
.addClass('test')
.text('123-4')
.appendTo('body');
//using substring ...
How to “properly” create a custom object in JavaScript?
...ot that if you detach a method from its owner:
var ts= mycircle.toString;
alert(ts());
then this inside the method won't be the Circle instance as expected (it'll actually be the global window object, causing widespread debugging woe). In reality this typically happens when a method is taken and ...