With params you can call your method like this: addTwoEach(1, 2, 3, 4, 5); Without params, you can’t. Additionally, you can call the method with an array as a parameter in both cases: addTwoEach(new int[] { 1, 2, 3, 4, 5 }); That is, params allows you to use a shortcut when calling the method. … Read more
Bare * is used to force the caller to use named arguments – so you cannot define a function with * as an argument when you have no following keyword arguments. See this answer or Python 3 documentation for more details.
myfun(*some_tuple) does exactly what you request. The * operator simply unpacks the tuple (or any iterable) and passes them as the positional arguments to the function. Read more about unpacking arguments.
Parameters in calls to functions in PowerShell (all versions) are space-separated, not comma separated. Also, the parentheses are entirely unneccessary and will cause a parse error in PowerShell 2.0 (or later) if Set-StrictMode -Version 2 or higher is active. Parenthesised arguments are used in .NET methods only. function foo($a, $b, $c) { “a: $a; b: … Read more
Tested as working: #Must be the first statement in your script (not counting comments) param([Int32]$step=30) $iTunes = New-Object -ComObject iTunes.Application if ($iTunes.playerstate -eq 1) { $iTunes.PlayerPosition = $iTunes.PlayerPosition + $step } Call it with powershell.exe -file itunesForward.ps1 -step 15 Multiple parameters syntax (comments are optional, but allowed): <# Script description. Some notes. #> param ( … Read more
It’s shorthand for tags.map(&:name.to_proc).join(‘ ‘) If foo is an object with a to_proc method, then you can pass it to a method as &foo, which will call foo.to_proc and use that as the method’s block. The Symbol#to_proc method was originally added by ActiveSupport but has been integrated into Ruby 1.8.7. This is its implementation: class … Read more
You could use the default-value syntax: somecommand ${1:-foo} The above will, as described in Bash Reference Manual – 3.5.3 Shell Parameter Expansion [emphasis mine]: If parameter is unset or null, the expansion of word is substituted. Otherwise, the value of parameter is substituted. If you only want to substitute a default value if the parameter … Read more
The single star * unpacks the sequence/collection into positional arguments, so you can do this: def sum(a, b): return a + b values = (1, 2) s = sum(*values) This will unpack the tuple so that it actually executes as: s = sum(1, 2) The double star ** does the same, only using a dictionary … Read more
The $@ variable expands to all command-line parameters separated by spaces. Here is an example. abc “$@” When using $@, you should (almost) always put it in double-quotes to avoid misparsing of arguments containing spaces or wildcards (see below). This works for multiple arguments. It is also portable to all POSIX-compliant shells. It is also … Read more
Just like any other simple command, [ … ] or test requires spaces between its arguments. if [ “$#” -ne 1 ]; then echo “Illegal number of parameters” fi Or if test “$#” -ne 1; then echo “Illegal number of parameters” fi Suggestions When in Bash, prefer using [[ ]] instead as it doesn’t do … Read more