Muktarul Khan Akash
Nov 2, 2020 · 2 min read

Easily hack fundamental JavaScript concepts with example

#javascript string

  1. String.charAt() => The String object’s charAt() method returns you a char from a string with her index number.

Example:

const sentence = “ The young boy jump over the child”;

const index = 6 ;

console.log(`the character at index ${index} is ${sentence. charAt(index)}`;

output => The character at index 6 is u

2. String.concat() => method concatenates the string arguments to the calling string and returns a new string.

Example:

const str1 = ‘I love’;

const str2 =’Bangladesh’;

cosole.log (str1.concat(‘ ’, str2));

output => I love Bangladesh

cosole.log (str2.concat(‘ ,’, str1));

output => Bangladesh, I love;

Syntax

str.concat(str2 [, ...strN])

3.String.endsWith() => method narrate whether a string ends with the characters of a specified string, returning true to false as appropriate.

Example:

const str1 = ‘You are the best!’;

console.log(str1.endsWith(‘best’, 17));
// expected output: true

const str2 = ‘Is this a question’;

console.log(str2.endsWith(‘?’));
// expected output: false

Syntax

str.endsWith(searchString[, length])

4.indexOf()=> method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex. Returns -1 if the value is not found.

Example:

const paragraph = ‘The quick brown fox jumps over the lazy dog. If the dog barked, was it really lazy?’;

const searchTerm = ‘dog’;
const indexOfFirst = paragraph.indexOf(searchTerm);

console.log(`The index of the first “${searchTerm}” from the beginning is ${indexOfFirst}`);
// expected output: “The index of the first “dog” from the beginning is 40"

console.log(`The index of the 2nd “${searchTerm}” is ${paragraph.indexOf(searchTerm, (indexOfFirst + 1))}`);
// expected output: “The index of the 2nd “dog” is 52"

Syntax

str.indexOf(searchValue [, fromIndex])

5.String.includes() =>the method determines whether one string may be found within another string, returning true or false as appropriate.

Example:

const sentence = ‘The quick brown fox jumps over the lazy dog.’;

const word = ‘fox’;

console.log(`The word “${word}” ${sentence.includes(word) ? ‘is’ : ‘is not’} in the sentence`);
// expected output: “The word “fox” is in the sentence”

Syntax

str.includes(searchString[, position])

6.lastIndexOf()=> the method returns the index within the calling String an object of the last occurrence of the specified value, searching backward from fromIndex. Returns -1 if the value is not found.

Example:

const paragraph = ‘The quick brown fox jumps over the lazy dog. If the dog barked, was it really lazy?’;

const searchTerm = ‘lazy’;

console.log(`The index of the first “${searchTerm}” from the end is ${paragraph.lastIndexOf(searchTerm)}`);
// expected output: “The index of the first “dog” from the end is 52"

Syntax

str.lastIndexOf(searchValue[, fromIndex])

Muktarul khan Akash

Web Development,Life-Style

Muktarul khan Akash

Hi, i am Muktarul khan Akash, i am a web developer. Iwill always publish some of my blog on various topics on web development.You can visit my blog to get daily blog updates on new web development.

Muktarul Khan Akash

Written by

Frontend web developer || Web developer || JavaScript developer

Muktarul khan Akash

Hi, i am Muktarul khan Akash, i am a web developer. Iwill always publish some of my blog on various topics on web development.You can visit my blog to get daily blog updates on new web development.