In PHP, a variable or array element which has never been set is different from one whose value is null; attempting to access such an unset value is a runtime error. That’s what you’re running into: the array $_POST does not have any element at the key “username”, so the interpreter aborts your program before … Read more
Never try to set the compiler in the CMakeLists.txt file. See the CMake FAQ about how to use a different compiler: https://gitlab.kitware.com/cmake/community/wikis/FAQ#how-do-i-use-a-different-compiler (Note that you are attempting method #3 and the FAQ says “(avoid)”…) We recommend avoiding the “in the CMakeLists” technique because there are problems with it when a different compiler was used for … Read more
Console.WriteLine(typeof(string).IsClass); // true It’s a reference type. It can’t be a value-type, as value-types need a known size for the stack etc. As a reference-type, the size of the reference is known in advance, even if the size of the string isn’t. It behaves like you expect a value-type to behave because it is immutable; … Read more
Use Write-Error to write to stderr. To redirect stderr to file use: Write-Error “oops” 2> /temp/err.msg or exe_that_writes_to_stderr.exe bogus_arg 2> /temp/err.msg Note that PowerShell writes errors as error records. If you want to avoid the verbose output of the error records, you could write out the error info yourself like so: PS> Write-Error “oops” -ev … Read more
Use strcmp() to compare the contents of strings: if (strcmp(var1, “dev”) == 0) { } Explanation: in C, a string is a pointer to a memory location which contains bytes. Comparing a char* to a char* using the equality operator won’t work as expected, because you are comparing the memory locations of the strings rather … Read more
If you intend to use the default VB6 Collection, then the easiest you can do is: col1.add array(“first key”, “first string”), “first key” col1.add array(“second key”, “second string”), “second key” col1.add array(“third key”, “third string”), “third key” Then you can list all values: Dim i As Variant For Each i In col1 Debug.Print i(1) Next … Read more
Yes. But place your “test” after the comma if you want the column… > A <- matrix(sample(1:12,12,T),ncol=4) > rownames(A) <- letters[1:3] > colnames(A) <- letters[11:14] > A[,”l”] a b c 6 10 1 see also help(Extract)
There is no scrollEnd event, but you can listen for the scroll event and check if it is still scrolling the window: var scrollTimeout; addEventListener(‘scroll’, function(e) { clearTimeout(scrollTimeout); scrollTimeout = setTimeout(function() { console.log(‘Scroll ended’); }, 100); });
As new processes fork in, PIDs will increase to a system-dependent limit and then wrap around. The kernel will not reuse a PID before this wrap-around happens. The limit (maximum number of pids) is /proc/sys/kernel/pid_max. The manual says: /proc/sys/kernel/pid_max (since Linux 2.5.34) This file specifies the value at which PIDs wrap around (i.e., the value … Read more
String s = “0.01”; double d = Double.parseDouble(s); int i = (int) d; The reason for the exception is that an integer does not hold rational numbers (= basically fractions). So, trying to parse 0.3 to a int is nonsense. A double or a float datatype can hold rational numbers. The way Java casts a … Read more