Codeflies Technologies Front end Developer Interview Questions, Process, and Tips

CSS stands for Cascading Style Sheets. It is used to style and layout web pages.

• CSS is used to add styles to HTML elements.

• There are three types of CSS: inline, internal, and external.

• Inline CSS is applied directly to an HTML element using the style attribute.

• Internal CSS is defined in the head section of an HTML document using the style tag.

• External CSS is defined in a separate file and linked to the HTML document usi

visibility:hidden hides the element but still takes up space, display:none hides the element and does not take up space.

• visibility:hidden keeps the element in the document flow and preserves its dimensions

• display:none removes the element from the document flow and does not preserve its dimensions

• visibility:hidden still allows the element to be interacted with, display:none does not

• visibility:hidden can still affect the...read more

Flexbox is a layout mode in CSS that allows you to create flexible and responsive layouts.

• Flexbox is used to align and distribute space among items in a container.

• It allows you to easily create complex layouts without using floats or positioning.

• Flexbox properties include display, flex-direction, justify-content, align-items, and flex-wrap.

• Example: display: flex; flex-direction: row; justify-content: space-between; ali...read more

let and var are both used for variable declaration in JavaScript, but they have some differences.

• let has block scope, while var has function scope

• let cannot be redeclared in the same scope, while var can

• let is not hoisted, while var is

• let is a relatively new addition to JavaScript (ES6), while var has been around since the beginning

JavaScript has 7 primitive data types: string, number, boolean, null, undefined, symbol, and bigint.

• String: a sequence of characters enclosed in quotes

• Number: integer or floating-point number

• Boolean: true or false

• Null: intentional absence of any object value

• Undefined: a declared variable without a value

• Symbol: a unique identifier

• Bigint: an integer with arbitrary precision

null means absence of value while undefined means a variable has been declared but not assigned a value.

• null is a value that represents no value or an empty value

• undefined means a variable has been declared but not assigned a value

• null is a primitive value while undefined is a type

• null is explicitly set while undefined is implicit

• null is falsy while undefined is also falsy

• null is an object while undefined is not an obj

An anonymous function is a function without a name, defined using function keyword and can be assigned to a variable.

• Anonymous functions are often used as callbacks or event handlers.

• They can be passed as arguments to other functions.

• They can be used to create closures.

• Example: const add = function(a, b) { return a + b; }

• Example: setTimeout(function() { console.log('Hello World!'); }, 1000);