Tutorial by Examples: argument

If you have an instance of a generic type but for some reason don't know the specific type, you might want to determine the generic arguments that were used to create this instance. Let's say someone created an instance of List<T> like that and passes it to a method: var myList = new List&lt...

Python has a variety of command-line switches which can be passed to py. These can be found by performing py --help, which gives this output on Python 3.4: Python Launcher usage: py [ launcher-arguments ] [ python-arguments ] script [ script-arguments ] Launcher arguments: -2 : Launch ...

Some functions only work on a certain type of argument: function foo(tab) return tab.bar end --> returns nil if tab has no field bar, which is acceptable --> returns 'attempt to index a number value' if tab is, for example, 3 --> which is unacceptable function kungfoo(tab) ...

When you create an argparse ArgumentParser() and run your program with '-h' you get an automated usage message explaining what arguments you can run your software with. By default, positional arguments and conditional arguments are separated into two categories, for example, here is a small script ...

Racket functions can also have keyword arguments, which are specified with a keyword followed by the argument expression. A keyword begins with the characters #:, so a keyword argument looks like #:keyword arg-expr. Within a function call this looks like (function #:keyword arg-expr). > (define ...

Python 3 allows you to define function arguments which can only be assigned by keyword, even without default values. This is done by using star * to consume additional positional parameters without setting the keyword parameters. All arguments after the * are keyword-only (i.e. non-positional) arg...

When given an argument, the when-statement matches the argument against the branches in sequence. The matching is done using the == operator which performs null checks and compares the operands using the equals function. The first matching one will be executed. when (x) { "English" -...

You can pass parameters to I18n t method: # Example config/locales/en.yml en: page: users: "%{users_count} users currently online" # In models, controller, etc... I18n.t('page.users', users_count: 12) # In views # ERB <%= t('page.users', users_count: 12) %> #S...

This is MATLAB's long-winded way of saying that it cannot find the function that you're trying to call. There are a number of reasons you could get this error: That function was introduced after your current version of MATLAB The MATLAB online documentation provides a very nice feature which allow...

The intent attribute of a dummy argument in a subroutine or function declares its intended use. The syntax is either one of intent(IN) intent(OUT) intent(INOUT) For example, consider this function: real function f(x) real, intent(IN) :: x f = x*x end function The intent(IN) specif...

When you create a function in TypeScript you can specify the data type of the function's arguments and the data type for the return value Example: function sum(x: number, y: number): number { return x + y; } Here the syntax x: number, y: number means that the function can accept two argum...

Example: function hello(name: string): string { return `Hello ${name}!`; } Here the syntax name: string means that the function can accept one name argument and this argument can only be string and (...): string { means that the return value can only be a string Usage: hello('StackOverfl...

<!-- <moduleDir>/etc/<area>/di.xml --> <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd"> <!-- ... --> <type name="Vendor\Namespace\Model\So...

Functions are objects in Julia. Like any other objects, they can be passed as arguments to other functions. Functions that accept functions are known as higher-order functions. For instance, we can implement an equivalent of the standard library's foreach function by taking a function f as the firs...

C++11 It's possible to write a generic function (for example min) which accepts various numerical types and arbitrary argument count by template meta-programming. This function declares a min for two arguments and recursively for more. template <typename T1, typename T2> auto min(const T1 &...

We can omit the argument in the call if that argument is an Optional Argument Every Optional Argument has its own default value It will take default value if we do not supply the value A default value of a Optional Argument must be a Constant expression. Must be a value type such as enum or s...

To create a function which accepts an undetermined number of arguments, there are two methods depending on your environment. 5 Whenever a function is called, it has an Array-like arguments object in its scope, containing all the arguments passed to the function. Indexing into or iterating over th...

K&R void* is a catch all type for pointers to object types. An example of this in use is with the malloc function, which is declared as void* malloc(size_t); The pointer-to-void return type means that it is possible to assign the return value from malloc to a pointer to any other type of ob...

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...