1.String :

JavaScript strings are for storing and manipulating text.In JavaScript, a string is a sequence of characters enclosed in single or double quotes. For example:

let firstName = 'Megha';
let lastName = "khatri";

2. JavaScript String Methods :

Strings have several built-in methods that can be used to manipulate and retrieve information from strings. Some examples include:

1. .length

The length property returns the length of a string:

let name = "Megha khatri";
console.log(name.length);  //output 12

2. .concat() :

This method concatenates (joins) two or more strings and returns a new string.

let firstName ="Megha";
let lastName = "Khatri";
let fullName = firstName.concat(" ",lastName);
console.log(fullName); // output "Megha Khatri"

3. .toUpperCase() :

This method converts all the characters in a string to uppercase.

let text = 'good morning';
console.log(text.toUpperCase()); //output 'GOOD MORNING'

4. .toLowerCase() :

This method converts all the characters in a string to lowercase.

let text = 'GOOD MORNING';
console.log(text.toLowerCase());  //output 'good morning'

4. .indexOf() :

This method returns the index of the first occurrence of a specified string value.

let text ='good noon';
console.log(text.indexOf('noon'));  // output 5

5. .slice() :

This method extracts a part of a string and returns a new string.The method takes 2 parameters: start position, and end position (end not included).

For example : Slice out a portion of a string from position 7 to position 13:

let text = "Apple, Banana, Kiwi";
let part = text.slice(7, 13); //output 'Banana'

6..substr() :

substr() is similar to slice().

let str = "Apple, Banana, Kiwi";
let part = str.substr(7, 6);

The difference is that the second parameter specifies the length of the extracted part.

7. replace()

The replace() method replaces a specified value with another value in a string.The replace() method returns a new string.The replace() method replaces only the first match

let text = "Please visit again!";
let newText = text.replace("again", "again in future");

8. trim() :

The trim() method removes whitespace from both sides of a string:

let text1 = "      Hello World!      ";
let text2 = text1.trim();

9. trimStart() :

The trimStart() method works like trim(), but removes whitespace only from the start of a string.

let text1 = "     Hello World!     ";
let text2 = text1.trimStart();

10. trimEnd()

The trimEnd() method works like trim(), but removes whitespace only from the end of a string.

let text1 = "     Hello World!     ";
let text2 = text1.trimEnd();