Tutorial by Examples: element

Accessing Elements

There are two primary ways of accessing elements in a std::vector index-based access iterators Index-based access: This can be done either with the subscript operator [], or the member function at(). Both return a reference to the element at the respective position in the std::vector (unles...

C++ • std::vector

Creating DOM elements

The jQuery function (usually aliased as $) can be used both to select elements and to create new elements. var myLink = $('<a href="http://stackexchange.com"></a>'); You can optionally pass a second argument with element attributes: var myLink = $('<a>', { 'href': 'h...

jQuery • DOM Manipulation

Manipulating element classes

Assuming the page includes an HTML element like: <p class="small-paragraph"> This is a small <a href="https://en.wikipedia.org/wiki/Paragraph">paragraph</a> with a <a class="trusted" href="http://stackexchange.com">link</a>...

jQuery • DOM Manipulation

Selecting elements using CSS selectors

String html = "<!DOCTYPE html>" + "<html>" + "<head>" + "<title>Hello world!</title>" + "</head>" + "<body>" + ...

Jsoup • Selectors

Joining array elements in a string

To join all of an array's elements into a string, you can use the join method: console.log(["Hello", " ", "world"].join("")); // "Hello world" console.log([1, 800, 555, 1234].join("-")); // "1-800-555-1234" As you can see in ...

JavaScript • Arrays

Giving an element a class

Classes are identifiers for the elements that they are assigned to. Use the class attribute to assign a class to an element. <div class="example-class"></div> To assign multiple classes to an element, separate the class names with spaces. <div class="class1 class2&...

HTML • Classes and IDs

Giving an element an ID

The ID attribute of an element is an identifier which must be unique in the whole document. Its purpose is to uniquely identify the element when linking (using an anchor), scripting, or styling (with CSS). <div id="example-id"></div> You should not have two elements with th...

HTML • Classes and IDs

Deleting Elements

Deleting the last element: std::vector<int> v{ 1, 2, 3 }; v.pop_back(); // v becomes {1, 2} Deleting all elements: std::vector<int> v{ 1, 2, 3 }; v.clear(); // v becomes an empty vector Deleting element by index: std::vect...

C++ • std::vector

Accessing elements

An std::map takes (key, value) pairs as input. Consider the following example of std::map initialization: std::map < std::string, int > ranking { std::make_pair("stackoverflow", 2), std::make_pair("docs-beta", 1) }; In an std::...

C++ • std::map

Deleting elements

Removing all elements: std::multimap< int , int > mmp{ {1, 2}, {3, 4}, {6, 5}, {8, 9}, {3, 4}, {6, 7} }; mmp.clear(); //empty multimap Removing element from somewhere with the help of iterator: std::multimap< int , int > mmp{ {1, 2}, {3, 4}, {6, 5}, {8, 9}, {3, 4}, {6, 7} }; ...

C++ • std::map

Inserting elements

An element can be inserted into a std::map only if its key is not already present in the map. Given for example: std::map< std::string, size_t > fruits_count; A key-value pair is inserted into a std::map through the insert() member function. It requires a pair as an argument: fruits_c...

C++ • std::map

Checking number of elements

The container std::map has a member function empty(), which returns true or false, depending on whether the map is empty or not. The member function size() returns the number of element stored in a std::map container: std::map<std::string , int> rank {{"facebook.com", 1} ,{"goo...

C++ • std::map

Finding an Element in std::vector

The function std::find, defined in the <algorithm> header, can be used to find an element in a std::vector. std::find uses the operator== to compare elements for equality. It returns an iterator to the first element in the range that compares equal to the value. If the element in question is...

C++ • std::vector

Convert elements to strings and concatenate them, separated by commas

// Java: String joined = things.stream() .map(Object::toString) .collect(Collectors.joining(", ")); // Kotlin: val joined = things.joinToString() // ", " is used as separator, by default

Kotlin • Java 8 Stream Equivalents

Output Element Using For and Form Attributes

The following demo features an <output> element's use of the [for] and [form] attributes. Keep in mind, <output> needs JavaScript in order to function. Inline JavaScript is commonly used in forms as this example demonstrates. Although the <input> elements are type="number&quot...

HTML • Output Element

Output Element with Attributes

HTML • Output Element

Iterating the elements of a map

import fmt people := map[string]int{ "john": 30, "jane": 29, "mark": 11, } for key, value := range people { fmt.Println("Name:", key, "Age:", value) } Note that when iterating over a map with a range loop, the iteration order i...

Go • Maps

Deleting a map element

The delete built-in function removes the element with the specified key from a map. people := map[string]int{"john": 30, "jane": 29} fmt.Println(people) // map[john:30 jane:29] delete(people, "john") fmt.Println(people) // map[jane:29] If the map is nil or ther...

Go • Maps

Finding out the Number of Elements in an Array

NSArray *myColors = [NSArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil]; NSLog (@"Number of elements in array = %lu", [myColors count]);

Objective-C Language • NSArray

Adding elements

NSMutableArray *myColors; myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil]; [myColors addObject: @"Indigo"]; [myColors addObject: @"Violet"]; //Add objects from an NSArray NSArray *myArray = @[@...

Objective-C Language • NSMutableArray