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Why aren't ◎ܫ◎ and ☺ valid JavaScript variable names?
... @Daniel Just tried this: var ab = 'ab'; ab = 'a<ZWNJ>b'; alert(ab); and it alerted ab with this warning: "Warning: assignment to undeclared variable ab". Since many pages are filled with warnings like that, it could likely go unnoticed, even by someone who was actually looking at t...
Limit file format when using ?
...
case 'jpg':
case 'bmp':
case 'png':
case 'tif':
alert('Allowed');
break;
default:
alert('Not allowed');
this.value = '';
}
};
<input type="file" id="someId" />
JSFiddle
...
Can you write nested functions in JavaScript?
...an treat functions like any other kind of object.
var foo = function () { alert('default function'); }
function pickAFunction(a_or_b) {
var funcs = {
a: function () {
alert('a');
},
b: function () {
alert('b');
}
};
foo = funcs[a_...
RGB to hex and hex to RGB
...urn "#" + componentToHex(r) + componentToHex(g) + componentToHex(b);
}
alert(rgbToHex(0, 51, 255)); // #0033ff
Converting the other way:
function hexToRgb(hex) {
var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
return result ? {
r: parseInt(result[1], 16...
How and why does 'a'['toUpperCase']() in JavaScript work?
...
foo.bar and foo['bar'] are equal so the code you posted is the same as
alert('a'.toUpperCase())
When using foo[bar] (note tha lack of quotes) you do not use the literal name bar but whatever value the variable bar contains. So using the foo[] notation instead of foo. allows you to use a dynami...
Is it possible to clone html element objects in JavaScript / JQuery?
...div>
Here is the javascript:
$("#foo2").click(function() {
//alert("clicked");
var value=$(this).html();
$("#foo1").html(value);
});
Here is the jsfiddle: http://jsfiddle.net/fritzdenim/DhCjf/
shar...
Can I read the hash portion of the URL on my server-side application (PHP, Ruby, Python, etc.)?
...me used within the URL via javascript using, as an example:
<script>alert(window.location.hash);</script>
The parse_url() function in PHP can work if you already have the needed URL string including the fragment (http://codepad.org/BDqjtXix):
<?
echo parse_url("http://foo?bar#fizz...
Difference between $(this) and event.target?
...head>
<script>
function mouseDown() {
alert(this);
}
</script>
</head>
<body>
<p onmouseup="mouseDown();alert(this);">Hi</p>
</body>
</html>
The content of alert windows after renderi...
Is there any way to call a function periodically in JavaScript?
...
You want setInterval():
var intervalID = setInterval(function(){alert("Interval reached");}, 5000);
The first parameter to setInterval() can also be a string of code to be evaluated.
You can clear a periodic function with:
clearInterval(intervalID);
...
JavaScript object: access variable property by name as string [duplicate]
... }
};
var filename = Test01[whatOption][whatColor];
alert(filename);
}
</script>
</head>
<body>
<p onclick="displayFile('rectangle', 'red')">[ Rec Red ]</p>
<br/>
<p onclick="displayFile('square', 'blue')">[ Sq Blue ...