大约有 47,000 项符合查询结果（耗时：0.0496秒） [XML]
How to remove the querystring and get only the url?
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+100
You can use strtok to get string before first occurence of ?
$url = strtok($_SERVER["REQUEST_URI"], '?');
strtok() represents the ...
Relative frequencies / proportions with dplyr
...n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That makes ...
Best way to make Java's modulus behave like it should with negative numbers?
...the negative values of a, since (a % b) is a negative value between -b and 0, (a % b + b) is necessarily lower than b and positive. The last modulo is there in case a was positive to begin with, since if a is positive (a % b + b) would become larger than b. Therefore, (a % b + b) % b turns it into s...
How do I verify that an Android apk is signed with a release certificate?
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edited Jan 27 '17 at 20:05
Eugene
1,59211 gold badge1111 silver badges3131 bronze badges
answered Au...
Why does Decimal.Divide(int, int) work, but not (int / int)?
How come dividing two 32 bit int numbers as ( int / int ) returns to me 0 , but if I use Decimal.Divide() I get the correct answer? I'm by no means a c# guy.
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Regex how to match an optional character
...e letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])[0-9]{3}([0-9]{4})([0-9]{2})([0-9]{2})
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CSS filter: make color image with transparency white
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You can use
filter: brightness(0) invert(1);
html {
background: red;
}
p {
float: left;
max-width: 50%;
text-align: center;
}
img {
display: block;
max-width: 100%;
}
.filter {
-webkit-filter: brightness(0) invert(1);
fi...
How to determine if a point is in a 2D triangle? [closed]
... d2 = sign(pt, v2, v3);
d3 = sign(pt, v3, v1);
has_neg = (d1 < 0) || (d2 < 0) || (d3 < 0);
has_pos = (d1 > 0) || (d2 > 0) || (d3 > 0);
return !(has_neg && has_pos);
}
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Redirect STDERR / STDOUT of a process AFTER it's been started, using command line?
... to the process in question using gdb, and run:
p dup2(open("/dev/null", 0), 1)
p dup2(open("/dev/null", 0), 2)
detach
quit
e.g.:
$ tail -f /var/log/lastlog &
[1] 5636
$ ls -l /proc/5636/fd
total 0
lrwx------ 1 myuser myuser 64 Feb 27 07:36 0 -> /dev/pts/0
lrwx------ 1 myuser myuser 6...
How do I truncate a .NET string?
...lue;
return value.Length <= maxLength ? value : value.Substring(0, maxLength);
}
}
Now we can write:
var someString = "...";
someString = someString.Truncate(2);
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