JavaScript string Reference includes JavaScript’s built-in string properties, methods, and behaviors that enable you to work with and manipulate text.
1. length
The length property returns the length of the given string.
Example:
let text = "Nilesh";
console.log("The Length of the Text Is: "text.length);
Output:
The Length of the Text Is: 6
2. charAt()
The charAt() gives the character at the given position(specified index). If you want to output the character at index position 10(m) then:
Example:
let text = "Hello from Nilesh"; console.log(text.charAt(10));
Output:
m
3. concat()
concat method joins two or more strings together.
Example:
let firstname = "Yadav";
let lastname = "Nilesh";
console.log("Full Name: "+firstname.concat(" ",lastname));
Output:
Full Name: Yadav Nilesh
The above code joins the strings of variables firstname and lastname and displays them together using concat().
4. charCodeAt()
It gives the Unicode of the character at a specified index. Unicode assigns a unique number to every character from every language and symbol set called a code point.
Example:
let a = "Hello coders";
console.log("The Unicode of e is: "+a.charcode(10));
Output:
The Unicode of e is: 101
5. includes()
It checks whether a string contains a certain word and returns true or false.
Example:
let string = "Hello Jatin";
console.log(string.includes("Jatin"));
Output:
true
6. indexOf()
It Returns the position of the first occurrence of a specified text in a string.
Example:
let string = "Hii Nilesh";
console.log(string.indexOf("Nilesh"));
Output:
4
This code gives the position of the first occurrence of string ‘Nilesh’ which is at index position 4.
7. lastIndexOf()
Returns the position of the last occurrence of a specified value in a string.
Example:
let string = "Nilesh Hii Nilesh";
console.log(string.lastIndexOf("Nilesh"));
Output:
13
8. slice()
Extracts a part of a string and returns a new string.
Example:
let string = "Web Devlopment is easy to learn"; console.log(string.slice(0,14));
Output:
Web Devlopment
9. substring()
It is similar to slice() but does not accept negative indices.
Example:
let wish = "Good Morning"; console.log(wish.substring(5,12));
Output:
Morning
10. replace()
Replace a specified value with another value in a string.
Example:
let string = "Good Morning";
console.log(string.replace("Morning", "Night"));
Output:
Good Night
11. toUpperCase()
toUpperCase() converts the string to upper case.
Example:
let string = "codespeedy"; console.log(string.toUpperCase());
Output:
CODESPEEDY
12.toLowerCase()
toLowerCase() converts the string to lowercase.
Example:
let string = "INTERNSHIP"; console.log(string.toLowerCase());
Output:
internship
13. startsWith()
It checks if a string starts with specified characters.
Example:
let string = "Nilesh is an intern in codespeedy";
console.log(string.startsWith("intern"));
Output:
false
14. endsWith()
It checks if a string ends with specified characters.
Example:
let string = "Nilesh is an intern in codespeedy";
console.log(string.endsWith("codespeedy"));
Output:
true
15. repeat()
This function repeats a given string several times and returns a new string.
Example:
let str = "Coders"; console.log(str.repeat(4));
Output:
CodersCodersCodersCoders
All these properties and methods can be used to perform operations on strings as per the user’s requirement.