Lambadas in kotlin programming language

-
Lambadas are similar to arrow functions in JavaScript they are a short alternative method to declare functions in kotlin programing language, You can create a function expression as;

val double = {num: Int -> num * 2}
val cube = { num: Int -> num * num * num}
val square = {num: Int ->
    val product = num * num
    product }

The last expression in a lambada is considered as a return value;
Parameters can be omitted, for a single parameter lambada the value of the omitted parameter is in the variable 'it'

Comments

Post a Comment

Popular posts from this blog

How to evaluate a string on a regular expression rule in JavaScript

-
JavaScript has a built in regular expression function for testing if a string arguments is matching the given regular expression rule; Syntax of the regular expression tester is as follows; /regex/.test(string) Take for instance you want to test if a string contains only alphanumeric upper and lower case characters, space and numbers; const str = "Eat code sleep" /[A-Z,a-z,0-9, ]*/.test(str) // returns boolean 'true' Or in another example; const str = "Eat, Code, Sleep" /[A-Z,a-z,0-9, ]*/.test(str) // returns boolean 'false' Because commas are not included in the regular expression match rules.
Read more

Get current url port, hostname and path in JavaScript

-
window.location is an Object with properties of current location namely window.location.href  returns the href url of the current page window.location.hostname  returns the domain name window.location.pathname  returns the pathname segment of the url window.location.protocol  returns the web protocol of the url window.location.assign ()  loads a new document
Read more

JavaScript intro to classes

-
Classes are objects 'functions which introduce inheritance parent child relationship in JavaScript it promotes code reusability which reduces the amount of code in a JavaScript application. JavaScript class decelerations start with keyword class proceeded by class name with a class body having a constructor along with methods for instance class human {     constructor(name) {          this.name = name;          this.gender = null;     }     great() {         return "Greetings " +         (this.gender == "male") ? "mr " : "mrs " + this.name     } } Child classes are created by adding the keyword extends followed by the parent class name and parent class methods can be called using the syntax super.+"method name"(parameters) class man extends human {   ...
Read more

Install steam locomotive sl using apt

-
sl or steam locomotive is a commandline application that displays steam locomotive "train" animations aimed to correct users who accidentally enter sl instead of ls.  initials sl stands for Steam Locomotive How to install ls or steam locomotive Assuming you've root privileges and installed apt package manager on your system Type sudo apt-get update sudo apt-get upgrade sudo apt-get install sl To test installation type sl If installation was successful You'll see an ASCII image of a train right in your terminal after few seconds it will stop
Read more

How to use canvas context rect method for drawing rectangles

-
canvas context rect method does as it says. It's used for drawing a rectangle on a canvas context Parameters context.rect(positionX, positionY, Width, Height) PositionX specifies the x coordinate at which the rectangle should be drawn at on the context PositionY specifies the y coordinate at which the rectangle should be drawn at on the context Width specifies the width of the rectangle Height specifies the height of the rectangle Stroking and filling the rectangle In order for the rectangle to be actually visible you have to either stroke it or fill it with a color. Stroke Stroking a rectangle means to draw a line that joins all of it's vertices To specify the fill color you should set it and call stroke to draw context.strokeStyle = "#colors" context.stroke() Fill Similar to srokings filling a rectangle means to paint it's inner bounding box with a specified color context.fillStyle = "#colors" context.fill() Example context.rect...
Read more