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01. What are truthy and falsy values?

Truthy values: Any numbers value truthy others than 0 and any string values truthy other than an empty string.

Falsy values: Any variable values likes(false,empty string, 0, undefined, nul, NaN)called falsy valuse.

02. What is the difference between null and undefined?

Undefined: Unintentionally missing values. undefined is negative/falsy values. undefined is variable declared but not the value set and function explicitly not a return value or function call but not parameters pass, and any object property access but this property not in an object this called undefined. undefined means a variable has been declared but not defined yet.

Null: Intentionally missing values called a null. and null is an…

React is a javascript library. It is a declarative, efficient, and flexible javascript library. It developed by Facebook. It’s also components-based architecture. But it’s not a framework.


It generally the entry point for react application into the browser’s DOM(Document Object Model). It has two arguments. The first one stands for what to render to the browser. It always reacts to elements. the second one stands for where to render the react elements on the browser.

02. Error Boundaries:

Error boundaries React components catch javascript errors anywhere in their child component tree, log those errors, and display a fallback UI…

01. Coding Style

Coding Style not mandatory to apply for your code. But coding style is a good practice and your code clean and readable to apply code style.

Code style applies some rules:

  1. A space between parameters,
  2. Curly brackets { on the same line, after space,
  3. A use semicolon mandatory for style,
  4. A space after for/if/while,
  5. A space between arguments etc.

O2. Comments

We know comments code structure single line or multi-line. we normally use the describe how and why code works.

when using comments:

  1. Architecture, high level-view,
  2. Function usages,
  3. Important solutions etc.

when not use comments :

  1. How…

Interesting javascript string methods Power

  1. concat() Method

concat(): Method:

concat () Method input string arguments and adding arguments return new concat() string arguments. Change original string.


conat str1 = ‘Concat(): Method:

Concat () Method input string arguments and adding arguments return new concat() string arguments. Change orginial string but bo effect.


conat str1 = ‘ Raju’;

concat str2 = ‘ Biswas’;

console.log(str1.concat(‘ ’, str2));

OutPut = ‘’Raju, Biswas’’’;

02. includes() Method.

Includes() is case sensitive, search one string if found within another string, includes return true or false.


const line = ‘ He goes to school late today.’;

const word = ‘late’;


I'm a Front-end Developer and Familiar with work's Backend. I enjoy working with Team as a leader or member.I Always learning New technology. I enjoy it.

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