JavaScript strings are the sequence of characters. In JavaScript, strings automatically convert the string to objects so that we can use string methods and properties also for primitive strings. It is used to represent and manipulate the sequence of characters.
In general, there are two ways to create a string in JavaScript. Either by using the new String() syntax or putting the value in quotes.
Example: This example, creates a string in JavaScript using the methods described above.
Javascript
let str1 = "Welcome to GeesforGeeks";let str2 = new String("Welcome Geeks");console.log(str1);console.log(str2); |
Welcome to GeesforGeeks [String: 'Welcome Geeks']
JavaScript String Methods and Property
String methods and properties are important to perform any operation on the given string, String indexes start from 0. The first character is in position 0 and the second in 1 and the same follows. We can call any of the pre-defined methods of JavaScript as it automatically converts from string primitive to objects.
Example:
let gfg= "neveropen"
Property:
JavaScript String length Property: This property returns the number of characters present in the string. In the case of an array, this property returns the number of elements present in the array.
Example: This example describes the JavaScript String Length property.
JavaScript
// JavaScript to illustrate length property function func() { // length property for string console.log("GFG".length)}func(); |
Output:
3
Methods:
Below are the following methods of the string:
Method 1: JavaScript slice(startIndex, endIndex) Method
This method extracts a part of the string based on the given stating-index and ending-index and returns a new string.
Example: This example describes the JavaScript String slice() method.
javascript
let A = 'Geeks for Geeks';b = A.slice(0,5);c = A.slice(6,9);d = A.slice(10);console.log(b);console.log(c);console.log(d); |
Geeks for Geeks
Method 2: JavaScript substring(startIndex, endIndex) Method
This method returns the part of the given string from the start index to the end index. Indexing starts from zero (0).
Javascript
let str = "Mind, Power, Soul";let part = str.substring(6, 11);console.log(part); |
Output:
Power
Method 3: JavaScript substr(start, length) Method
This method returns the specified number of characters from the specified index from the given string. It basically extracts a part of the original string.
Javascript
let str = "Mind, Power, Soul";let part = str.substr(6, 5);console.log(part); |
Power
Method 4: JavaScript replace(replaceValue, replaceWithValue)
This method replaces a part of the given string with another string or a regular expression. The original string will remain unchanged.
Javascript
let str = "Mind, Power, Soul";let part = str.replace("Power", "Space");console.log(part); |
Output:
Mind, Space, Soul
Method 5: JavaScript replaceAll(regexp | substr , newSubstr | function)
This method returns a new string after replacing all the matches of a string with a specified string or a regular expression. The original string is left unchanged after this operation.
Javascript
let str = "Mind, Power, Power, Soul";let part = str.replaceAll("Power", "Space");console.log(part); |
Output:
Mind, Space, Space, Soul
Method 6: JavaScript toUpperCase(stringVariable)
This method converts all the characters present in the String to upper case and returns a new String with all characters in upper case. This method accepts single parameter stringVariable string that you want to convert in upper case.
Example: This example describes the JavaScript String toUpperCase() method.
javascript
let gfg = 'GFG 'let neveropen = 'stands-for-neveropen';console.log(neveropen.toUpperCase(neveropen)) ; |
Output:
STANDS-FOR-GEEKSFORGEEKS
Method 7: JavaScript toLowerCase(stringVariable)
This method converts all the characters present in the so lowercase and returns a new string with all the characters in lowercase.
Example: This example describes the JavaScript String toLowerCase() method.
javascript
let gfg = 'GFG ';let neveropen = 'stands-for-neveropen';console.log(neveropen.toLowerCase(neveropen)); |
Output:
stands-for-neveropen
Method 8: JavaScript concat(objectOfString) Method
This method combines the text of two strings and returns a new combined or joined string. To concatenate two strings, we use the concat() method on one object of string and send another object of string as a parameter. This method accepts one argument. The variable contains text in double quotes or single quotes.
Example: This example describes the JavaScript String concat() method.
javascript
let gfg = 'GFG ';let neveropen = 'stands for neveropen';// Accessing concat method on an object// of String passing another object // as a parameterconsole.log(gfg.concat(neveropen)); |
Output:
GFG stands for neveropen
Method 9: JavaScript trim() Method
This method is used to remove either white spaces from the given string. This method returns a new string with removed white spaces. This method is called on a String object. This method doesn’t accept any parameter.
Example: This example describes the JavaScript String trim() method.
javascript
let gfg = 'GFG ';let neveropen = 'stands-for-neveropen';// Storing new object of string// with removed white spaceslet newGfg = gfg.trim();// Old lengthconsole.log(gfg.length);// New lengthconsole.log(newGfg.length) |
Output:
7
3
Method 10: JavaScript trimStart() Method
This method removes whitespace from the beginning of a string. The value of the string is not modified in any manner, including any whitespace present after the string.
Javascript
let str = " Soul";console.log(str)let part = str.trimStart();console.log(part); |
Output:
Soul
Soul
Method 11: JavaScript trimEnd() Method
This method removes white space from the end of a string. The value of the string is not modified in any manner, including any white-space present before the string.
Javascript
let str = "Soul ";console.log(str)let part = str.trimEnd();console.log(part); |
Output:
Soul
Soul
Method 12: JavaScript padStart() Method
This method pad a string with another string until it reaches the given length. The padding is applied from the left end of the string.
Javascript
let stone = "Soul";stone = stone.padStart(9,"Mind ");console.log(stone); |
Output:
Mind Soul
Method 13: JavaScript padEnd() Method
This method pad a string with another string until it reaches the given length. The padding is applied from the right end of the string.
Javascript
let stone = "Soul";stone = stone.padEnd(10," Power");console.log(stone); |
Output:
Soul Power
Method 14: JavaScript charAt(indexOfCharacter) Method:
This method returns the character at the specified index. String in JavaScript has zero-based indexing.
Example: This example describes the JavaScript string charAt() method.
javascript
let gfg = 'neveropen';let neveropen = 'GfG is the best platform to learn and\n'+'experience Computer Science.';// Print the string as it isconsole.log(gfg); console.log(neveropen); // As string index starts from zero// It will return first character of stringconsole.log(gfg.charAt(0)); console.log(neveropen.charAt(5)); |
Output:
neveropen
GfG is the best platform to learn
and experience Computer Science.
G
s
Method 15: JavaScript charCodeAt(indexOfCharacter) Method
This method returns a number that represents the Unicode value of the character at the specified index. This method accepts one argument.
Example: This example describes the JavaScript String charCodeAt() Method.
javascript
let gfg = 'neveropen';let neveropen = 'GfG is the best platform\n\to learn and experience\n\Computer Science.';// Return a number indicating Unicode// value of character at index 0 ('G')console.log(gfg.charCodeAt(0));console.log(neveropen.charCodeAt(5)); |
Output:
71
115
Method 16: JavaScript split(character) Method
This method splits the string into an array of sub-strings. This method returns an array. This method accepts a single parameter character on which you want to split the string.
Example: This example describes the JavaScript String split() method.
javascript
let gfg = 'GFG 'let neveropen = 'stands-for-neveropen'// Split string on '-'. console.log(neveropen.split('-')) |
Output:
['stands', 'for', 'neveropen']
String Method Summary:
|
Instance Methods |
Description |
|---|---|
| at() | Find the character at the specified index. |
| anchor() | Creates an anchor element that is used as a hypertext target. |
| charAt() | Returns that character at the given index of the string. |
| charCodeAt() | Returns a Unicode character set code unit of the character present at the index in the string. |
| codePointAt() | Return a non-negative integer value i.e, the code point value of the specified element. |
| concat() | Join two or more strings together in JavaScript. |
| endsWith() | Whether the given string ends with the characters of the specified string or not. |
| includes() | Returns true if the string contains the characters, otherwise, it returns false. |
| indexOf() | Finds the index of the first occurrence of the argument string in the given string. |
| lastIndexOf() | Finds the index of the last occurrence of the argument string in the given string. |
| localeCompare() | Compare any two elements and returns a positive number |
| match() | Search a string for a match against any regular expression. |
| matchAll() | Return all the iterators matching the reference string against a regular expression. |
| normalize() | Return a Unicode normalization form of a given input string. |
| padEnd() | Pad a string with another string until it reaches the given length from rightend. |
| padStart() | Pad a string with another string until it reaches the given length from leftend. |
| repeat() | Build a new string containing a specified number of copies of the string. |
| replace() | Replace a part of the given string with some another string or a regular expression |
| replaceAll() | Returns a new string after replacing all the matches of a string with a specified string/regex. |
| search() | Search for a match in between regular expressions and a given string object. |
| slice() | Return a part or slice of the given input string. |
| split() | Separate given string into substrings using a specified separator provided in the argument. |
| startsWith() | Check whether the given string starts with the characters of the specified string or not. |
| substr() | Returns the specified number of characters from the specified index from the given string. |
| substring() | Return the part of the given string from the start index to the end index. |
| toLowerCase() | Converts the entire string to lowercase. |
| toLocaleLowerCase() | Returns the calling string value converted to a lowercase letter. |
| toLocaleUpperCase() | Returns the calling string value converted to a uppercase letter. |
| toUpperCase() | Converts the entire string to uppercase. |
| toString() | Return the given string itself. |
| trim() | Remove the white spaces from both ends of the given string. |
| trimEnd() | Remove white space from the end of a string. |
| trimStart() | Remove white space from the start of a string. |
| valueOf() | Return the value of the given string. |
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This method is used to make String iterable. [@@iterator]() returns an iterator object which iterates over all code points of the String. |
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This method is used to create a string from the given sequence of UTF-16 code units. This method returns a string, not a string object. |
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This method in JavaScript that is used to return a string or an element for the given sequence of code point values (ASCII value). |
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This method is used to check if the string contains a lone surrogate or not |
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This is a static method that is used to get the raw string form of template literals. These strings do not process escape characters. |
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toWellFormed() |
This method is used to return where all lone surrogates of this string are replaced with the Unicode replacement character |
We have a complete list of Javascript string methods, to check those please go through this JavaScript String reference article.
