Updated on Kisan Patel
A JavaScript string can be both a primitive data type or an object. As a primitive type, it joins with four other JavaScript primitive types: number, Boolean (true or false), null (no value), and undefined (unknown).
A string is zero or more characters delimited by quotes, either single quotes.
‘This is a string’
Or double quotes.
“This is a string”
A string object is called String.
A String object can be instantiated using the JavaScript new operator, to create a new object instance.
var name = new String("Kisan Patel");
Once instantiated, any one of the available string properties can be accessed on it, such as in the following code, where the string is lowercased using the String object method toLowerCase.
var newName = name.toLowerCase(); // new string is now kisan patel
If you access the String constructor without using new, you will create a string literal rather than a String object.
var name = String("Kisan Patel");
| Method | Description |
| charAt() | Returns the character at the specified index |
| charCodeAt() | Returns the Unicode of the character at the specified index |
| concat() | Joins two or more strings, and returns a copy of the joined strings |
| fromCharCode() | Converts Unicode values to characters |
| indexOf() | Returns the position of the first found occurrence of a specified value in a string |
| lastIndexOf() | Returns the position of the last found occurrence of a specified value in a string |
| localeCompare() | Compares two strings in the current locale |
| match() | Searches a string for a match against a regular expression, and returns the matches |
| replace() | Searches a string for a specified value, or a regular expression, and returns a new string where the specified values are replaced |
| search() | Searches a string for a specified value, or regular expression, and returns the position of the match |
| slice() | Extracts a part of a string and returns a new string |
| split() | Splits a string into an array of substrings |
| substr() | Extracts the characters from a string, beginning at a specified start position, and through the specified number of character |
| substring() | Extracts the characters from a string, between two specified indices |
| toLocaleLowerCase() | Converts a string to lowercase letters, according to the host’s locale |
| toLocaleUpperCase() | Converts a string to uppercase letters, according to the host’s locale |
| toLowerCase() | Converts a string to lowercase letters |
| toString() | Returns the value of a String object |
| toUpperCase() | Converts a string to uppercase letters |
| trim() | Removes whitespace from both ends of a string |
| valueOf() | Returns the primitive value of a String object |