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The : symbol is used for more than one purpose in PythonAs slice operator with sequence −The − operator slices a part from a sequence object such as list, tuple or string. It takes two arguments. First is the index of start of slice and second is index of end of slice. Both operands are optional. If first operand is omitted, it is 0 by default. If second is omitted, it is set to end of sequence.>>> a=[1, 2, 3, 4, 5] >>> a[1:3] [2, 3] >>> a[:3] [1, 2, 3] >>> a[2:] [3, 4, 5] >>> s='computer' >>> s[:3] ... Read More
In Java, a final variable can a be assigned only once. It can be assigned during declaration or at a later stage. A final variable if not assigned any value is treated as a blank final variable. Following are the rules governing initialization of a blank final variable.A blank instance level final variable cannot be left uninitialized.The blank Instance level final variable must be initialized in each constructor.The blank Instance level final variable cannot be initialized in class methods.A blank static final variable cannot be left uninitialized.The static final variable must be initialized in a static block.A static final variable cannot ... Read More
java.util.concurrent.The callable object can return the computed result done by a thread in contrast to a runnable interface which can only run the thread. The Callable object returns a Future object which provides methods to monitor the progress of a task being executed by a thread. The future object can be used to check the status of a Callable and then retrieve the result from the Callable once the thread is done. It also provides timeout functionality.Syntax//submit the callable using ThreadExecutor //and get the result as a Future object Future result10 = executor.submit(new FactorialService(10)); //get the result using ... Read More
You can use PHP array in JavaScript. It works for the single as well as the multidimensional array. Use the json_encode() method to achieve this.Let’s say Our PHP array is −$myArr = array('Amit', 'amit@example.com');Converting PHP array into JavaScript. var arr = ; Now, let’s finally learn how to access it to output the email −document.write(arr[1]);
In the case of Event-driven programming, we pass a reference to a function which will get called when an event occurs. This mechanism is termed as a callback. Java does not support function pointers. So we can not implement the same direction. But using interfaces we can achieve the same very easily.In the example below, we've made a callback when a button is clicked. See the steps −Create an interface ClickEventHandler with a single method handleClick().Create a ClickHandler class which implements this interface ClickEventHandler.Create a Button class which will call ClickHandler when it's click method is called.Test the application.ExampleLive Demo//Step ... Read More
To get the time difference between two timestamps, try to run the following code. Here, we are calculating the total number of hours, minutes and seconds between two timestamps −ExampleLive Demo JavaScript Dates var date1, date2; date1 = new Date( "Jan 1, 2018 11:10:05" ); document.write(""+date1); date2 = new Date( "Jan 1, 2018 08:15:10" ); document.write(""+date2); var res ... Read More
When a method is invoked on a null reference, it throws NullPointerException but in case of the static method, we can make it possible using cast expression. See the example below −ExampleLive Demopublic class Tester { public static void display(){ System.out.println("display"); } private void print() { System.out.println("print"); } public static void main(String[] args) { //Scenario 1: //Calling a method on null reference //causes NullPointerException try { Tester test = null; ... Read More
Use the justify-content-start class in Bootstrap to justify content in the beginning.The justify-content-*-start class is used in Bootstrap to justify content in the beginning on different screen sizes like the following on small, medium, and large screen sizes −You can try to run the following code to implement the justify-content-*-start class −ExampleLive Demo Bootstrap Example Entertainment Bollywood Tollywood Hollywood Bollywood Tollywood Hollywood Bollywood Tollywood Hollywood
To align flex items on small, medium, large and extra large screen size, use the justify-content-*-start class.Let us see first for small screen size − Interface Packages Multithreading In the same way, implement it for medium, large and extra large screen size like the following −justify-content-md-start: Medium Screen size justify-content-lg-start: Large Screen size justify-content-xl-start: Extra Large Screen SizeYou can try to run the following code to align flex items in the start on different screen sizes −ExampleLive Score Bootstrap Example Java Topics Interface Packages Multithreading Interface Packages Multithreading Interface Packages Multithreading
To add top rounded corners to an element, use the rounded-top class in Bootstrap 4.I have taken div as the element −Let us learn how to add top rounded corners to an element −ExampleLive Demo Bootstrap Example .new { width: 80px; height: 80px; background-color: #EE6D1E; margin: 20px; } Rounded Corner We have a rectangle with top rounded corner: