Yes, that’s a good approximation of how the for loop construct is implemented. It certainly matches the for loop statement documentation: The expression list is evaluated once; it should yield an iterable object. An iterator is created for the result of the expression_list. The suite is then executed once for each item provided by the … Read more
The options of FOR, IF and REM are only parsed up to the special character phase. Or better the commands are detected in the special character phase and a different parser is activated then. Therefore it’s not possible to use delayed expansion nor FOR-Parameter in the options. These tests fail with errors for /F %%O … Read more
As @Pavel explained, it is not simply possible to traverse a record, like you could traverse an array. But there are several ways around it – depending on your exact requirements. Ultimately, since you want to return all values in the same column, you need to cast them to the same type – text is … Read more
The reason it doesn’t compile is that in C++ a function parameter such as char array[] is adjusted to char* array. Your function really looks like int print_a(char* array) { …. } and the range based loops cannot deal with a pointer. One solution is to pass the array by reference. C++ does not allow … Read more
The label gets updated all right, but the GUI isn’t redrawn before the end of your loop. Here’s what you can do about it: Move your long-running loop to a secondary thread, drawing the GUI is happening in the main thread. Call app.processEvents() in your loop. This gives Qt the chance to process events and … Read more
It really depends on what you call ‘performance’ 🙂 If you mean minimum execution time, well, sometimes *fun are faster (for example, cellfun(‘isempty’, …); (yes, string argument!) for sure beats the loop version). Sometimes a loop is faster. If you’re on a Matlab version < 2006, go for the *fun functions by default. If you’re … Read more
Do you want the closure over the variable or the value? For example, package main import “fmt” func VariableLoop() { f := make([]func(), 3) for i := 0; i < 3; i++ { // closure over variable i f[i] = func() { fmt.Println(i) } } fmt.Println(“VariableLoop”) for _, f := range f { f() } … Read more
With && you can execute more than one commands, one after another: Runtime.getRuntime().exec(“cmd /c \”start somefile.bat && start other.bat && cd C:\\test && test.exe\””); Using multiple commands and conditional processing symbols You can run multiple commands from a single command line or script using conditional processing symbols. When you run multiple commands with conditional processing … Read more
No you cannot rely on this behaviour. Modifying the vector inside the loop results in undefined behaviour because the iterators used by the loop are invalidated when the vector is modified. The range based for loop for ( range_declaration : range_expression) loop_statement is essentially equivalent to { auto && __range = range_expression ; for (auto … Read more