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How do I calculate the normal vector of a line segment?
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answered Aug 7 '09 at 8:49
Oren TrutnerOren Trutner
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How do I check for null values in JavaScript?
... will check for empty strings (""), null, undefined, false and the numbers 0 and NaN
Please note that if you are specifically checking for numbers it is a common mistake to miss 0 with this method, and num !== 0 is preferred (or num !== -1 or ~num (hacky code that also checks against -1)) for funct...
Get all child views inside LinearLayout at once
...earLayout ll = …
final int childCount = ll.getChildCount();
for (int i = 0; i < childCount; i++) {
View v = ll.getChildAt(i);
// Do something with v.
// …
}
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'str' object does not support item assignment in Python
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105
In Python, strings are immutable, so you can't change their characters in-place.
You can, howe...
How can I convert the “arguments” object to an array in JavaScript?
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730
+100
ES6 usin...
Show an image preview before upload
... // read the image file as a data URL.
reader.readAsDataURL(this.files[0]);
};
Here's a good article on using the File APIs in JavaScript.
The code snippet in the HTML example below filters out images from the user's selection and renders selected files into multiple thumbnail previews:
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Get css top value as number not as string?
... by Ben): You should give the radix too:
parseInt($('#elem').css('top'), 10);
Forces it to be parsed as a decimal number, otherwise strings beginning with '0' might be parsed as an octal number (might depend on the browser used).
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Nullable type issue with ?: Conditional Operator
Could someone explain why this works in C#.NET 2.0:
5 Answers
5
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How to set enum to null
...e for enums that cannot be null by having the FIRST value in the enum (aka 0) be the default value. For example in a case of color None.
public Color myColor = Color.None;
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Generate random 5 characters string
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$rand = substr(md5(microtime()),rand(0,26),5);
Would be my best guess--Unless you're looking for special characters, too:
$seed = str_split('abcdefghijklmnopqrstuvwxyz'
.'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
.'0123456789!@#$%^&*()...