Tutorial by Examples: in

git diff This will show the unstaged changes on the current branch from the commit before it. It will only show changes relative to the index, meaning it shows what you could add to the next commit, but haven't. To add (stage) these changes, you can use git add. If a file is staged, but was modi...

Python's string type provides many functions that act on the capitalization of a string. These include : str.casefold str.upper str.lower str.capitalize str.title str.swapcase With unicode strings (the default in Python 3), these operations are not 1:1 mappings or reversible. Most of thes...

str.split(sep=None, maxsplit=-1) str.split takes a string and returns a list of substrings of the original string. The behavior differs depending on whether the sep argument is provided or omitted. If sep isn't provided, or is None, then the splitting takes place wherever there is whitespace. Howe...

Python's str type also has a method for replacing occurences of one sub-string with another sub-string in a given string. For more demanding cases, one can use re.sub. str.replace(old, new[, count]): str.replace takes two arguments old and new containing the old sub-string which is to be replace...

function waitFunc(){ console.log("This will be logged every 5 seconds"); } window.setInterval(waitFunc,5000);

window.setInterval() returns an IntervalID, which can be used to stop that interval from continuing to run. To do this, store the return value of window.setInterval() in a variable and call clearInterval() with that variable as the only argument: function waitFunc(){ console.log("This wil...

window.setTimout() returns a TimeoutID, which can be used to stop that timeout from running. To do this, store the return value of window.setTimeout() in a variable and call clearTimeout() with that variable as the only argument: function waitFunc(){ console.log("This will not be logged a...

git merge incomingBranch This merges the branch incomingBranch into the branch you are currently in. For example, if you are currently in master, then incomingBranch will be merged into master. Merging can create conflicts in some cases. If this happens, you will see the message Automatic merge ...

Functions in Swift may return values, throw errors, or both: func reticulateSplines() // no return value and no error func reticulateSplines() -> Int // always returns a value func reticulateSplines() throws // no return value, but may throw an error func reticulat...

The following examples will use this array to demonstrate accessing values var exampleArray:[Int] = [1,2,3,4,5] //exampleArray = [1, 2, 3, 4, 5] To access a value at a known index use the following syntax: let exampleOne = exampleArray[2] //exampleOne = 3 Note: The value at index two is th...

It is possible to send a value to the generator by passing it to the next() method. function* summer() { let sum = 0, value; while (true) { // receive sent value value = yield; if (value === null) break; // aggregate values sum += value; ...

A string in PHP is a series of single-byte characters (i.e. there is no native Unicode support) that can be specified in four ways: Single Quoted Displays things almost completely "as is". Variables and most escape sequences will not be interpreted. The exception is that to display a lit...

There are multiple ways to append values onto an array var exampleArray = [1,2,3,4,5] exampleArray.append(6) //exampleArray = [1, 2, 3, 4, 5, 6] var sixOnwards = [7,8,9,10] exampleArray += sixOnwards //exampleArray = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] and remove values from an array exampleAr...

The basic syntax of SELECT with WHERE clause is: SELECT column1, column2, columnN FROM table_name WHERE [condition] The [condition] can be any SQL expression, specified using comparison or logical operators like >, <, =, <>, >=, <=, LIKE, NOT, IN, BETWEEN etc. The following ...

SELECT PhoneNumber, Email, PreferredContact FROM Customers This statement will return the columns PhoneNumber, Email, and PreferredContact from all rows of the Customers table. Also the columns will be returned in the sequence in which they appear in the SELECT clause. The re...

Definition: In computing, an event is an action or occurrence recognized by software that may be handled by the software. Computer events can be generated or triggered by the system, by the user or in other ways. Definition Source HTML events are "things" that happen to HTML ele...

The removeEventListener() method removes event handlers that have been attached with the addEventListener() method: element.removeEventListener("mousemove", myFunction); Everything (eventname, function, and options) in the removeEventListener must match the one set when adding the even...

One of the most commonly used events is waiting for the document to have loaded, including both script files and images. The load event on document is used for this. document.addEventListener('load', function() { console.log("Everything has now loaded!"); }); Sometimes you try to ...

A hash in Ruby is an object that implements a hash table, mapping keys to values. Ruby supports a specific literal syntax for defining hashes using {}: my_hash = {} # an empty hash grades = { 'Mark' => 15, 'Jimmy' => 10, 'Jack' => 10 } A hash can also be created using the standard new...

Individual values of a hash are read and written using the [] and []= methods: my_hash = { length: 4, width: 5 } my_hash[:length] #=> => 4 my_hash[:height] = 9 my_hash #=> {:length => 4, :width => 5, :height => 9 } By default, accessing a key which has not been added t...