In this chapter, we are going to learn Java String Class Methods. In our previous chapter, we learned about Java String and String vs StringBuffer vs String Builder.
Therefore, its time to perform some operations on Java String Class. For that, Java provided some inbuild set of methods.
Java String Class Methods
You can use 40+ built-in methods in Java String Class.
| Method | Description |
|---|---|
| charAt() | Returns the character at the specified index (position) |
| codePointAt() | Returns the Unicode of the character at the specified index |
| codePointBefore() | Returns the Unicode of the character before the specified index |
| codePointCount() | Returns the Unicode in the specified text range of this String |
| compareTo() | Compares two strings lexicographically |
| compareToIgnoreCase() | Compares two strings lexicographically, ignoring case differences |
| concat() | Appends a string to the end of another string |
| contains() | Checks whether a string contains a sequence of characters |
| contentEquals() | Checks whether a string contains the exact same sequence of characters |
| copyValueOf() | Returns a String that represents the characters of the character array |
| endsWith() | Checks whether a string ends with the specified character(s) |
| equals() | Compares two strings. Returns true if the strings are equal, and false if not |
| equalsIgnoreCase() | Compares two strings, ignoring case considerations |
| format() | Returns a formatted string using the specified locale, format string, and arguments |
| getBytes() | Encodes this String into a sequence of bytes using the named charset, storing the result into a new byte array |
| getChars() | Copies characters from a string to an array of chars |
| hashCode() | Returns the hash code of a string |
| indexOf() | Returns the position of the first found occurrence of specified characters in a string |
| intern() | Returns the index within this string of the first occurrence of the specified character |
| isEmpty() | Checks whether a string is empty or not |
| lastIndexOf() | Returns the position of the last found occurrence of specified characters in a string |
| length() | Returns the length of a specified string |
| matches() | Returns the match of string against a regular expression |
| offsetByCodePoints() | Returns the index within this String that is offset from the given index by codePointOffset code points |
| regionMatches() | Tests if two string regions are equal |
| replace() | Searches a string for a specified value, and returns a new string where the specified values are replaced |
| replaceFirst() | Replaces the first occurrence of a substring that matches the given regular expression |
| replaceAll() | Replaces all occurrences of the string that matches the given regular expression |
| split() | Splits a string into an array of substrings |
| startsWith() | Checks whether a string starts with specified characters |
| subSequence() | Returns a new character sequence that is a subsequence of this sequence |
| substring() | Extracts the characters from specified position, and returns the specified number of character |
| toCharArray() | Converts this string to a new character array |
| toLowerCase() | Converts a string to lower case letters |
| toString() | Returns the value of a String object |
| toUpperCase() | Converts a string to upper case letters |
| trim() | Removes whitespace from both ends of a string |
| valueOf() | Returns the primitive value of a String object |
How to Use the Java String Method:
Let’s take an example of some Java String Class methods.
public class Practise {
public static void main(String[] args) {
String myString = "Hello World";
// charAt() Example
char value1 = myString.charAt(2);
System.out.println(value1);
// prints :: l
// codePointAt() Example
int value2 = myString.codePointAt(3);
System.out.println(value2);
// prints :: unicode of char at index 3 i.e 108
// length() Example
int value3 = myString.length();
System.out.println(value3);
// prints :: length of string i.e 11
}
}