大约有 46,000 项符合查询结果（耗时：0.0539秒） [XML]
Why can't decimal numbers be represented exactly in binary?
...to SO about floating-point representation. For example, the decimal number 0.1 doesn't have an exact binary representation, so it's dangerous to use the == operator to compare it to another floating-point number. I understand the principles behind floating-point representation.
...
add column to mysql table if it does not exist
...
Note that INFORMATION_SCHEMA isn't supported in MySQL prior to 5.0. Nor are stored procedures supported prior to 5.0, so if you need to support MySQL 4.1, this solution isn't good.
One solution used by frameworks that use database migrations is to record in your database a revision numbe...
Bash if [ false ] ; returns true
...
answered Oct 29 '13 at 22:06
chepnerchepner
357k4646 gold badges352352 silver badges475475 bronze badges
...
How to append contents of multiple files into one file
...
10 Answers
10
Active
...
Check a collection size with JSTL
...
<c:if test="${companies.size() > 0}">
</c:if>
This syntax works only in EL 2.2 or newer (Servlet 3.0 / JSP 2.2 or newer). If you're facing a XML parsing error because you're using JSPX or Facelets instead of JSP, then use gt instead of >.
<c...
Using CSS how to change only the 2nd column of a table
...
answered Mar 29 '10 at 0:04
Nick Craver♦Nick Craver
580k125125 gold badges12551255 silver badges11351135 bronze badges
...
In C, how should I read a text file and print all strings
...chunks, but without dynamic memory allocation, you can do:
#define CHUNK 1024 /* read 1024 bytes at a time */
char buf[CHUNK];
FILE *file;
size_t nread;
file = fopen("test.txt", "r");
if (file) {
while ((nread = fread(buf, 1, sizeof buf, file)) > 0)
fwrite(buf, 1, nread, stdout);
...
How to get a index value from foreach loop in jstl
... |
edited Jun 4 '14 at 20:55
Paul Gray
53011 gold badge55 silver badges99 bronze badges
answered Sep 1...
How to find an available port?
...
If you don't mind the port used, specify a port of 0 to the ServerSocket constructor and it will listen on any free port.
ServerSocket s = new ServerSocket(0);
System.out.println("listening on port: " + s.getLocalPort());
If you want to use a specific set of ports, then th...
Which terminal command to get just IP address and nothing else?
...
You can write a script that only return the IP like:
/sbin/ifconfig eth0 | grep 'inet addr' | cut -d: -f2 | awk '{print $1}'
For MAC:
ifconfig | grep "inet " | grep -v 127.0.0.1 | cut -d\ -f2
Or for linux system
hostname -i | awk '{print $3}' # Ubuntu
hostname -i # Debian
...