Tutorial by Examples: me

One can give a function as many arguments as one wants, the only fixed rules are that each argument name must be unique and that optional arguments must be after the not-optional ones: def func(value1, value2, optionalvalue=10): return '{0} {1} {2}'.format(value1, value2, optionalvalue1) Wh...

Arbitrary number of positional arguments: Defining a function capable of taking an arbitrary number of arguments can be done by prefixing one of the arguments with a * def func(*args): # args will be a tuple containing all values that are passed in for i in args: print(i) fun...

The increment and decrement operators exist in prefix and postfix form. int a = 1; int b = 1; int tmp = 0; tmp = ++a; /* increments a by one, and returns new value; a == 2, tmp == 2 */ tmp = a++; /* increments a by one, but returns old value; a == 3, tmp == 2 */ tmp = --b; ...

There is a problem when using optional arguments with a mutable default type (described in Defining a function with optional arguments), which can potentially lead to unexpected behaviour. Explanation This problem arises because a function's default arguments are initialised once, at the point whe...

This a Basic example for using the MVVM model in a windows desktop application, using WPF and C#. The example code implements a simple "user info" dialog. The View The XAML <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> ...

Calculating the length of the hypotenuse math.hypot(2, 4) # Just a shorthand for SquareRoot(2**2 + 4**2) # Out: 4.47213595499958 Converting degrees to/from radians All math functions expect radians so you need to convert degrees to radians: math.radians(45) # Convert 45 degrees t...

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...

The <select> element generates a drop-down menu from which the user can choose an option. <select name=""> <option value="1">One</option> <option value="2">Two</option> <option value="3">Three</option> ...

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 ...

When type is called with three arguments it behaves as the (meta)class it is, and creates a new instance, ie. it produces a new class/type. Dummy = type('OtherDummy', (), dict(x=1)) Dummy.__class__ # <type 'type'> Dummy().__class__.__class__ # <type 'type'> It is po...

Determine whether an array is empty or return its size var exampleArray = [1,2,3,4,5] exampleArray.isEmpty //false exampleArray.count //5 Reverse an Array Note: The result is not performed on the array the method is called on and must be put into its own variable. exampleArray = exampleArray...

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 ...

When the commits on two branches don't conflict, Git can automatically merge them: ~/Stack Overflow(branch:master) » git merge another_branch Auto-merging file_a Merge made by the 'recursive' strategy. file_a | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

One method is available for counting the number of occurrences of a sub-string in another string, str.count. str.count(sub[, start[, end]]) str.count returns an int indicating the number of non-overlapping occurrences of the sub-string sub in another string. The optional arguments start and end ...

The <article> element contains self-contained content like articles, blog posts, user comments or an interactive widget that could be distributed outside the context of the page, for example by RSS. When article elements are nested, the contents of the inner article node should be related t...

The <main> element contains the main content for your web page. This content is unique to the individual page, and should not appear elsewhere on the site. Repeating content like headers, footers, navigation, logos, etc., is placed outside the element. The <main> element should only e...

Swift label.textAlignment = NSTextAlignment.left //or the shorter label.textAlignment = .left Any value in the NSTextAlignment enum is valid: .left, .center, .right, .justified, .natural Objective-C label.textAlignment = NSTextAlignmentLeft; Any value in the NSTextAlignment enum is vali...

Use new Date() to generate a new Date object containing the current date and time. Note that Date() called without arguments is equivalent to new Date(Date.now()). Once you have a date object, you can apply any of the several available methods to extract its properties (e.g. getFullYear() to get t...

Magic (also called dunder as an abbreviation for double-underscore) methods in Python serve a similar purpose to operator overloading in other languages. They allow a class to define its behavior when it is used as an operand in unary or binary operator expressions. They also serve as implementation...

After starting a merge, you might want to stop the merge and return everything to its pre-merge state. Use --abort: git merge --abort