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Generate random numbers uniformly over an entire range
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Why rand is a bad idea
Most of the answers you got here make use of the rand function and the modulus operator. That method may not generate numbers uniformly (it depends on the range and the value of RAND_MAX), and is therefore disco...
How to check that a string is a palindrome using regular expressions?
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The answer to this question is that "it is impossible". More specifically, the interviewer is wondering if you paid attention in your computational theory class.
In your computational theory class you learned about finite state machines. A ...
What's the best way to detect a 'touch screen' device using JavaScript?
...-in that's for use on both desktop and mobile devices. I wondered if there is a way with JavaScript to detect if the device has touch screen capability. I'm using jquery-mobile.js to detect the touch screen events and it works on iOS, Android etc., but I'd also like to write conditional statements b...
Why do we use __init__ in Python classes?
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By what you wrote, you are missing a critical piece of understanding: the difference between a class and an object. __init__ doesn't initialize a class, it initializes an instance of a class or an object. Each dog has colour, but dogs as a class don't. ...
Has reCaptcha been cracked / hacked / OCR'd / defeated / broken? [closed]
... gave a talk at OWASP a few months ago explaining just that - the question is very specific, so I will provide for a demonstration.
But first, I will reiterate that demonstration aside, re-read the other comments, since it's truth that CAPTCHA is pointless and not helpful, irrelevant of implementati...
How to compare strings in Bash
... do we use quotes around $x?
You want the quotes around $x, because if it is empty, your Bash script encounters a syntax error as seen below:
if [ = "valid" ]; then
Non-standard use of == operator
Note that Bash allows == to be used for equality with [, but this is not standard.
Use either t...
What are bitwise operators?
... it in either an academic or professional setting, so stuff like these bitwise operators really escapes me.
9 Answers
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Benefits of using the conditional ?: (ternary) operator
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I would basically recommend using it only when the resulting statement is extremely short and represents a significant increase in conciseness over the if/else equivalent without sacrificing readability.
Good example:
int result = Check() ? 1 : 0;
Bad example:
int result = FirstCheck() ? 1 ...
PSQLException: current transaction is aborted, commands ignored until end of transaction block
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I got this error using Java and PostgreSQL doing an insert on a table. I will illustrate how you can reproduce this error:
org.postgresql.util.PSQLException: ERROR:
current transaction is aborted, commands ignored until end of tran...
Check if a number is int or float
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Use isinstance.
>>> x = 12
>>> isinstance(x, int)
True
>>> y = 12.0
>>> isinstance(y, float)
True
So:
>>> if isinstance(x, int):
print 'x is a int!'
x is a int!
_EDIT:_
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