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Is std::vector so much slower than plain arrays?
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UseVector completed in 4.412 seconds
UseVectorPushBack completed in 8.017 seconds
The whole thing completed in 14.626 seconds
So array is twice as quick as vector.
But after looking at the code in more detail this is expected; as you run across the vector twice and the array only once. ...
Generating random numbers in Objective-C
...a head mainly, and I want a way to generate a pseudo-random number between 0 and 74. In Java I would use the method:
13 Ans...
Using grep to search for a string that has a dot in it
I am trying to search for a string 0.49 (with dot) using the command
9 Answers
9
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Convert a character digit to the corresponding integer in C
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As per other replies, this is fine:
char c = '5';
int x = c - '0';
Also, for error checking, you may wish to check isdigit(c) is true first. Note that you cannot completely portably do the same for letters, for example:
char c = 'b';
int x = c - 'a'; // x is now not necessarily 1
Th...
How do I get Month and Date of JavaScript in 2 digit format?
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("0" + this.getDate()).slice(-2)
for the date, and similar:
("0" + (this.getMonth() + 1)).slice(-2)
for the month.
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How to format numbers? [duplicate]
...I first wrote this answer, but the current status looks good.
var n = 100000;
var value = n.toLocaleString(
undefined, // leave undefined to use the browser's locale,
// or use a string like 'en-US' to override it.
{ minimumFractionDigits: 2 }
);
console.log(value);
// In en-US,...
How to change the opacity (alpha, transparency) of an element in a canvas element after it has been
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309
I am also looking for an answer to this question, (to clarify, I want to be able to draw an ima...
Return 0 if field is null in MySQL
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Use IFNULL:
IFNULL(expr1, 0)
From the documentation:
If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2. IFNULL() returns a numeric or string value, depending on the context in which it is used.
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Why does this code using random strings print “hello world”?
...onstructed with a specific seed parameter (in this case -229985452 or -147909649), it follows the random number generation algorithm beginning with that seed value.
Every Random constructed with the same seed will generate the same pattern of numbers every time.
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What's wrong with using == to compare floats in Java?
...urrentSectionID) < epsilon)
where epsilon is a very small number like 0.00000001, depending on the desired precision.
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