Tutorial by Examples: ti

We can illustrate this problem with the following pseudo-code function foo() { global $bob; $bob->doSomething(); } Your first question here is an obvious one Where did $bob come from? Are you confused? Good. You've just learned why globals are confusing and considered a bad p...

Bool is a Boolean type with two possible values: true and false. let aTrueBool = true let aFalseBool = false Bools are used in control-flow statements as conditions. The if statement uses a Boolean condition to determine which block of code to run: func test(_ someBoolean: Bool) { if som...

Creating immutable arrays: NSArray *myColors = [NSArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil]; // Using the array literal syntax: NSArray *myColors = @[@"Red", @"Green", @"Blue", @"Yellow"]; ...

Remove at specific index: [myColors removeObjectAtIndex: 3]; Remove the first instance of a specific object: [myColors removeObject: @"Red"]; Remove all instances of a specific object: [myColors removeObjectIdenticalTo: @"Red"]; Remove all objects: [myColors removeAl...

NSMutableArray *myColors = [NSMutableArray arrayWithObjects: @"red", @"green", @"blue", @"yellow", nil]; NSArray *sortedArray; sortedArray = [myColors sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

You can "overwrite" a language declaration: <p lang="en">This English sentence contains the German word <span lang="de">Hallo</span>.</p>

The <section> element represents a generic section to thematically group content. Every section, typically, should be able to be identified with a heading element as a child of the section. You can use the <section> element within an <article> and vice-versa. Every section shou...

The (?(DEFINE)...) construct lets you define subpatterns you may reference later through recursion. When encountered in the pattern it will not be matched against. This group should contain named subpattern definitions, which will be accessible only through recursion. You can define grammars this w...

Subpatterns can be referenced with their relative group number: (?-1) will recurse into the previous group (?+1) will recurse into the next group Also usable with the \g<N> syntax.

Documentation comments are placed directly above the method or class they describe. They begin with three forward slashes ///, and allow meta information to be stored via XML. /// <summary> /// Bar method description /// </summary> public void Bar() { } Information in...

The built-in function len returns the number of elements in a map m := map[string]int{} len(m) // 0 m["foo"] = 1 len(m) // 1 If a variable points to a nil map, then len returns 0. var m map[string]int len(m) // 0

In a normal string, the backslash character is the escape character, which instructs the compiler to look at the next character(s) to determine the actual character in the string. (Full list of character escapes) In verbatim strings, there are no character escapes (except for "" which is ...

In functions taking callable as an argument, you can also put a string with PHP built-in function. It's common to use trim as array_map parameter to remove leading and trailing whitespace from all strings in the array. $arr = [' one ', 'two ', ' three']; var_dump(array_map('trim', $arr)); ...

To parse lots of parameters, the prefered way of doing this is using a while loop, a case statement, and shift. shift is used to pop the first parameter in the series, making what used to be $2, now be $1. This is useful for processing arguments one at a time. #!/bin/bash # Load the user define...

Most databases do not have a native way of generating a series of numbers for ad-hoc use; however, common table expressions can be used with recursion to emulate that type of function. The following example generates a common table expression called Numbers with a column i which has a row for numbe...

WITH RECURSIVE ManagedByJames(Level, ID, FName, LName) AS ( -- start with this row SELECT 1, ID, FName, LName FROM Employees WHERE ID = 1 UNION ALL -- get employees that have any of the previously selected rows as manager SELECT ManagedByJames.Level + 1, ...

BuildConfigField Gradle allows buildConfigField lines to define constants. These constants will be accessible at runtime as static fields of the BuildConfig class. This can be used to create flavors by defining all fields within the defaultConfig block, then overriding them for individual build fla...

MATLAB supports (and encourages) vectorized operations on vectors and matrices. For example, suppose we have A and B, two n-by-m matrices and we want C to be the element-wise product of the corresponding elements (i.e., C(i,j) = A(i,j)*B(i,j)). The un-vectorized way, using nested loops is as follo...

length counts the occurences of elements a in a foldable structure t a. ghci> length [7, 2, 9] -- t ~ [] 3 ghci> length (Right 'a') -- t ~ Either e 1 -- 'Either e a' may contain zero or one 'a' ghci> length (Left "foo") -- t ~ Either String 0 ghci> length (3, True) ...

The function strtok breaks a string into a smaller strings, or tokens, using a set of delimiters. #include <stdio.h> #include <string.h> int main(void) { int toknum = 0; char src[] = "Hello,, world!"; const char delimiters[] = ", !"; char *to...