Tutorial by Examples: ar

Optional parameters can be specified after required parameters, by using &OPTIONAL keyword. There may be multiple optional parameters after it. (defun foobar (x y &optional z) (format t "X (~s) and Y (~s) are required.~@ Z (~s) is optional.~%" x y z)) ...

Global named functions are defined with DEFUN. (defun foobar () "Optional documentation string. Can contain line breaks. Must be at the beginning of the function body. Some will format the docstring so that lines are indented to match the first line, although the built-in DESCRIBE-func...

A single rest-parameter can be given with the keyword &REST after the required arguments. If such a parameter exists, the function can take a number of arguments, which will be grouped into a list in the rest-parameter. Note that the variable CALL-ARGUMENTS-LIMIT determines the maximum number of...

The &AUX keyword can be used to define local variables for the function. They are not parameters; the user cannot supply them. &AUX variables are seldomly used. You can always use LET instead, or some other way of defining local variables in the function body. &AUX variables have the a...

Keyword parameters can be defined with the &KEY keyword. They are always optional (see the Optional Parameters example for details of the definition). There may be multiple keyword parameters. (defun foobar (x y &key (z "Default" zp)) (format t "X (~s) and Y (~s) are requi...

The search pattern can also be a regular expression. Running: grep '^[A-Z]' someFile.txt When someFile.txt contains: fred 14 m foo sam 68 m bar christina 83 f baz bob 22 m qux Sam 41 m quux Will produce the output: Sam 41 m quux since this is the only line in someFile.txt starting wi...

To access a member of a class, you need to have a "handle" to the particular instance, as either the instance itself, or a pointer or reference to it. Given a class instance, you can point to various of its members with a pointer-to-member, IF you get the syntax correct! Of course, the poi...

A static member variable is just like an ordinary C/C++ variable, except with scope: It is inside a class, so it needs its name decorated with the class name; It has accessibility, with public, protected or private. So, if you have access to the static member variable and decorate it correctl...

The lubridate package provides convenient functions to format date and datetime objects from character strings. The functions are permutations of LetterElement to parseBase R equivalentyyear%y, %Ym (with y and d)month%m, %b, %h, %Bdday%d, %ehhour%H, %I%pm (with h and s)minute%Msseconds%S e.g. ymd(...

You can alternatively use an Object Declaration that contains the main function for a Kotlin program. package my.program object App { @JvmStatic fun main(args: Array<String>) { println("Hello World") } } The class name that you will run is the name of you...

$this->helper('checkout/url')->getCartUrl(); OR Mage::helper('checkout/url')->getCartUrl();

Sometimes, it's not possible to list the number of parameters a function could need. Consider a sum function: func sum(_ a: Int, _ b: Int) -> Int { return a + b } This works fine for finding the sum of two numbers, but for finding the sum of three we'd have to write another function: f...

/** * Parameters * * @param int $int * @param string $string * @param array $array * @param bool $bool */ function demo_param($int, $string, $array, $bool) { } /** * Parameters - Optional / Defaults * * @param int $int * @param string $string * @param ...

<PROJECT_ROOT>\app\build.gradle is specific for app module. <PROJECT_ROOT>\build.gradle is a "Top-level build file" where you can add configuration options common to all sub-projects/modules. If you use another module in your project, as a local library you would have another...

Each pair in the dictionary is an instance of KeyValuePair with the same type parameters as the Dictionary. When you loop through the dictionary with For Each, each iteration will give you one of the Key-Value Pairs stored in the dictionary. For Each kvp As KeyValuePair(Of String, String) In curren...

Dim extensions As New Dictionary(Of String, String) _ from { { "txt", "notepad" }, { "bmp", "paint" }, { "doc", "winword" } } This creates a dictionary and immediately fills it with three KeyValuePairs. You can also add new val...

When you want to allow only certain keys in your arrays, especially when the array comes from request parameters, you can use array_intersect_key together with array_flip. $parameters = ['foo' => 'bar', 'bar' => 'baz', 'boo' => 'bam']; $allowedKeys = ['foo', 'bar']; $filteredParameters =...

Dictionaries are implemented in a Dict core library. A dictionary mapping unique keys to values. The keys can be any comparable type. This includes Int, Float, Time, Char, String, and tuples or lists of comparable types. Insert, remove, and query operations all take O(log n) time. Unlike Tu...

Comparable types are primitive types that can be compared using comparison operators from Basics module, like: (<), (>), (<=), (>=), max, min, compare Comparable types in Elm are Int, Float, Time, Char, String, and tuples or lists of comparable types. In documentation or type definitio...

From the official documentation: Gradle. dependencies { compile "com.squareup.picasso:picasso:2.5.2" } Maven: <dependency> <groupId>com.squareup.picasso</groupId> <artifactId>picasso</artifactId> <version>2.5.2</version> </dep...