大约有 48,000 项符合查询结果（耗时：0.0627秒） [XML]
How do Trigonometric functions work?
... a standard interval. For starters, you could reduce angles to be between 0 and 360 degrees. But by using a few identities, you realize you could get by with less. If you calculate sines and cosines for angles between 0 and 45 degrees, you can bootstrap your way to calculating all trig functions f...
How dangerous is it to compare floating point values?
...nt the actual result. An easy example where you can see this is adding x = 0x1fffffe and y = 1 as floats. Here, x has 24 bits of precision in the mantissa (ok) and y has just 1 bit, but when you add them, their bits are not in overlapping places, and the result would need 25 bits of precision. Inste...
How can I parse a string with a comma thousand separator to a number?
I have 2,299.00 as a string and I am trying to parse it to a number. I tried using parseFloat , which results in 2. I guess the comma is the problem, but how would I solve this issue the right way? Just remove the comma?
...
How do I test if a variable is a number in Bash?
...
One approach is to use a regular expression, like so:
re='^[0-9]+$'
if ! [[ $yournumber =~ $re ]] ; then
echo "error: Not a number" >&2; exit 1
fi
If the value is not necessarily an integer, consider amending the regex appropriately; for instance:
^[0-9]+([.][0-9]+)?$
....
Build.scala, % and %% symbols meaning
...%%:
val appDependencies = Seq(
"org.scala-tools" % "scala-stm_2.9.1" % "0.3"
)
Assuming the scalaVersion for your build is 2.9.1, the following is identical:
val appDependencies = Seq(
"org.scala-tools" %% "scala-stm" % "0.3"
)
As you can see above, if you use %%, you don't have to sp...
Bash Script: count unique lines in file
...
306
You can use the uniq command to get counts of sorted repeated lines:
sort ips.txt | uniq -c
...
Class with Object as a parameter
...
answered Sep 11 '11 at 0:46
unutbuunutbu
665k138138 gold badges14831483 silver badges14721472 bronze badges
...
Disable Maven warning message - “Selected war files include a WEB-INF/web.xml which will be ignored”
...
I got rid of this warning in maven 3.0.1 with the following build configuration (i believe perhaps web.xml is added to the project by other means, and should't be packaged by default):
<project>
...
<build>
<plugins>
...
MySQL - How to select data by string length
...
502
You are looking for CHAR_LENGTH() to get the number of characters in a string.
For multi-byte...
Sending a notification from a service in Android
...
109
Both Activity and Service actually extend Context so you can simply use this as your Context wi...