Tutorial by Examples: arguments

process.argv is an array containing the command line arguments. The first element will be node, the second element will be the name of the JavaScript file. The next elements will be any additional command line arguments. Code Example: Output sum of all command line arguments index.js var sum = 0...

function transform(fn, arr) { let result = []; for (let el of arr) { result.push(fn(el)); // We push the result of the transformed item to result } return result; } console.log(transform(x => x * 2, [1,2,3,4])); // [2, 4, 6, 8] As you can see, our transform fun...

proc myproc {} { puts "hi" } myproc # => hi An empty argument list (the second argument after the procedure name, "myproc") means that the procedure will not accept arguments.

proc myproc {alpha beta} { ... set foo $alpha set beta $bar ;# note: possibly useless invocation } myproc 12 34 ;# alpha will be 12, beta will be 34 If the argument list consists of words, those will be the names of local variables in the procedure, and their initi...

### Definition proc myproc {alpha {beta {}} {gamma green}} { puts [list $alpha $beta $gamma] } ### Use myproc A # => A {} green myproc A B # => A B green myproc A B C # => A B C This procedure accepts one, two, or three arguments: those parameters whose names are the fi...

proc myproc args { ... } proc myproc {args} { ... } ;# equivalent If the special parameter name args is the last item in the argument list, it receives a list of all arguments at that point in the command line. If there are none, the list is empty. There can be arguments, including optional one...

Command line arguments passed to awk are stored in the internal array ARGV of ARGC elements. The first element of the array is the program name. For example: awk 'BEGIN { for (i = 0; i < ARGC; ++i) { printf "ARGV[%d]=\"%s\"\n", i, ARGV[i] } }' arg1 arg2 arg3 ...

If you ever need an array that consists of extra arguments that you may or may not expect to have, apart from the ones you specifically declared, you can use the array rest parameter inside the arguments declaration as follows: Example 1, optional arguments into an array: function printArgs(arg1, ...

Assignment arguments appear at the end of an awk invocation, in the same area as file variables, both -v assignments and argument assignments must match the following regular expression. (assuming a POSIX locale) ^[[:alpha:]_][[:alnum:]_]*= The following example assumes a file file containing th...

Subroutine arguments in Perl are passed by reference, unless they are in the signature. This means that the members of the @_ array inside the sub are just aliases to the actual arguments. In the following example, $text in the main program is left modified after the subroutine call because $_[0] in...

A method can take an array parameter and destructure it immediately into named local variables. Found on Mathias Meyer's blog. def feed( amount, (animal, food) ) p "#{amount} #{animal}s chew some #{food}" end feed 3, [ 'rabbit', 'grass' ] # => "3 rabbits chew some gra...

arguments object behave different in strict and non strict mode. In non-strict mode, the argument object will reflect the changes in the value of the parameters which are present, however in strict mode any changes to the value of the parameter will not be reflected in the argument object. function...

Command line arguments parsing is Go is very similar to other languages. In you code you just access slice of arguments where first argument will be the name of program itself. Quick example: package main import ( "fmt" "os" ) func main() { progName := o...

An interesting but rather unknown usage of Active Patterns in F# is that they can be used to validate and transform function arguments. Consider the classic way to do argument validation: // val f : string option -> string option -> string let f v u = let v = defaultArg v "Hello&quo...

In functions, you can define a number of mandatory arguments: def fun1(arg1, arg2, arg3): return (arg1,arg2,arg3) which will make the function callable only when the three arguments are given: fun1(1, 2, 3) and you can define the arguments as optional, by using default values: def fun...

When you want to create a function that can accept any number of arguments, and not enforce the position or the name of the argument at "compile" time, it's possible and here's how: def fun1(*args, **kwargs): print(args, kwargs) The *args and **kwargs parameters are special parame...

Often beginning MATLAB developers will use MATLAB's editor to write and edit code, in particular custom functions with inputs and outputs. There is a Run button at the top that is available in recent versions of MATLAB: Once the developer finishes with the code, they are often tempted to push th...

This basic example counts at different rates on two threads that we name sync (main) and async (new thread). The main thread counts to 15 at 1Hz (1s) while the second counts to 10 at 0.5Hz (2s). Because the main thread finishes earlier, we use pthread_join to make it wait async to finish. #include ...

There are two common ways to encode a POST request body: URL encoding (application/x-www-form-urlencoded) and form data (multipart/form-data). Much of the code is similar, but the way you construct the body data is different. Sending a request using URL encoding Be it you have a server for your s...

Function arguments can be passed "By Reference", allowing the function to modify the variable used outside the function: function pluralize(&$word) { if (substr($word, -1) == 'y') { $word = substr($word, 0, -1) . 'ies'; } else { $word .= 's'; } } $w...