The idiomatic approach in Go is to write a for loop like this. for i := 1; i <= 10; i++ { fmt.Println(i) } There’s definitely advantages in ranges and they’re used in many other languages, but a Go design principle is to only introduce an abstraction if the benefits significantly outweigh the costs (including … Read more
The following will do it if, as I assume by your use of ./a.out, you’re on a UNIX-type platform. for number in 1 2 3 4 ; do \ ./a.out $$number ; \ done Test as follows: target: for number in 1 2 3 4 ; do \ echo $$number ; \ done produces: 1 … Read more
(Update: My other answer here lays out the non-jQuery options much more thoroughly. The third option below, jQuery.each, isn’t in it though.) Four options: Generic loop: var i; for (i = 0; i < substr.length; ++i) { // do something with `substr[i]` } or in ES2015+: for (let i = 0; i < substr.length; ++i) … Read more
Looping through the characters of a std::string, using a range-based for loop (it’s from C++11, already supported in recent releases of GCC, clang, and the VC11 beta): std::string str = ???; for(char& c : str) { do_things_with(c); } Looping through the characters of a std::string with iterators: std::string str = ???; for(std::string::iterator it = str.begin(); … Read more
First of all you should be absolutely sure you need to iterate through each row — set based operations will perform faster in every case I can think of and will normally use simpler code. Depending on your data it may be possible to loop using just SELECT statements as shown below: Declare @Id int … Read more
There is no for-loop, only the while-loop: DECLARE @i int = 0 WHILE @i < 20 BEGIN SET @i = @i + 1 /* do some work */ END
It’s not that i– is faster than i++. Actually, they’re both equally fast. What takes time in ascending loops is evaluating, for each i, the size of your array. In this loop: for(var i = array.length; i–;) You evaluate .length only once, when you declare i, whereas for this loop for(var i = 1; i … Read more
Command line usage: for /f %f in (‘dir /b c:\’) do echo %f Batch file usage: for /f %%f in (‘dir /b c:\’) do echo %%f Update: if the directory contains files with space in the names, you need to change the delimiter the for /f command is using. for example, you can use the … Read more
You can use a range with a step size of 2: Python 2 for i in xrange(0,10,2): print(i) Python 3 for i in range(0,10,2): print(i) Note: Use xrange in Python 2 instead of range because it is more efficient as it generates an iterable object, and not the whole list.
Old question but the remaining answers are outdated as of C++11 – you can use a ranged based for loop and simply do: std::map<std::string, std::map<std::string, std::string>> mymap; for(auto const &ent1 : mymap) { // ent1.first is the first key for(auto const &ent2 : ent1.second) { // ent2.first is the second key // ent2.second is the … Read more