instance-methods.md

Comprehensive List of Instance Methods in the String Class

Method	Description	Return Type	Example
length()	Returns the length of the string.	int	str.length();
charAt(int index)	Returns the character at the specified index.	char	str.charAt(0);
substring(int beginIndex, int endIndex)	Returns a substring between the specified indices.	String	str.substring(0, 4);
equals(Object obj)	Checks if two strings are equal.	boolean	str.equals("Hello");
equalsIgnoreCase(String anotherString)	Compares two strings, ignoring case differences.	boolean	str.equalsIgnoreCase("hello");
indexOf(String str)	Returns the index of the first occurrence of the specified substring.	int	str.indexOf("H");
lastIndexOf(String str)	Returns the index of the last occurrence of the specified substring.	int	str.lastIndexOf("o");
contains(CharSequence s)	Checks if the string contains the specified sequence.	boolean	str.contains("ell");
toLowerCase()	Converts all characters in the string to lowercase.	String	str.toLowerCase();
toUpperCase()	Converts all characters in the string to uppercase.	String	str.toUpperCase();
replace(char oldChar, char newChar)	Replaces all occurrences of a character with another character.	String	str.replace('H', 'h');
split(String regex)	Splits the string into an array of substrings based on the specified regex.	String[]	str.split(" ");
trim()	Removes leading and trailing whitespace from the string.	String	str.trim();
translateEscapes()	Returns a string whose value is this string, with escape sequences translated as if in a string literal.	String	str.translateEscapes();
chars()	Returns a stream of int zero-extending the char values from this sequence.	IntStream	str.chars();
compareTo(String anotherString)	Compares two strings lexicographically.	int	str.compareTo("Hello");
compareToIgnoreCase(String anotherString)	Compares two strings lexicographically, ignoring case differences.	int	str.compareToIgnoreCase("hello");
concat(String str)	Concatenates the specified string to the current string.	String	str.concat(" world");
formatted(Object... args)	Returns a formatted string using the specified arguments.	String	str.formatted("Hello %s", "world");
contentEquals(CharSequence seq)	Compares the string to the specified sequence of characters.	boolean	str.contentEquals("Hello");
contentEquals(StringBuffer sb)	Compares the string to the specified StringBuffer.	boolean	str.contentEquals(new StringBuffer("Hello"));
describeConstable()	Describes the string constant, if any.	Optional<String>	str.describeConstable();
endsWith(String suffix)	Checks if the string ends with the specified suffix.	boolean	str.endsWith("world");
getBytes()	Encodes the string into a byte array.	byte[]	str.getBytes();
getClass()	Returns the runtime class of the string.	Class<?>	str.getClass();
getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)	Copies characters from the string into a destination array.	void	str.getChars(0, 5, dest, 0);
hashCode()	Returns the hash code of the string.	int	str.hashCode();
indent(int n)	Indents the string with the specified number of spaces.	String	str.indent(4);
indexOf(String str)	Returns the index of the first occurrence of the substring.	int	str.indexOf("world");
indexOf(String str, int fromIndex)	Returns the index of the first occurrence of the substring from the specified index.	int	str.indexOf("world", 5);
indexOf(int ch)	Returns the index of the first occurrence of the character.	int	str.indexOf('H');
indexOf(int ch, int fromIndex)	Returns the index of the first occurrence of the character from the specified index.	int	str.indexOf('H', 2);
lines()	Returns a stream of lines from the string.	Stream<String>	str.lines();
replace(char oldChar, char newChar)	Replaces all occurrences of a character with another character.	String	str.replace('H', 'h');
replaceAll(String regex, String replacement)	Replaces each substring matching the regular expression with the given replacement.	String	str.replaceAll("world", "everyone");
replaceFirst(String regex, String replacement)	Replaces the first substring matching the regular expression with the given replacement.	String	str.replaceFirst("world", "everyone");
repeat(int count)	Returns a string that is a repeated concatenation of the string.	String	str.repeat(3);
intern()	Returns a canonical representation for the string.	String	str.intern();
isBlank()	Checks if the string is empty or contains only white space.	boolean	str.isBlank();
isEmpty()	Checks if the string is empty.	boolean	str.isEmpty();
matches(String regex)	Checks if the string matches the specified regular expression.	boolean	str.matches("\\d+");
stripIndent()	Removes the indentation from the string.	String	str.stripIndent();
stripLeading()	Removes leading white space from the string.	String	str.stripLeading();
toCharArray()	Converts the string into a character array.	char[]	str.toCharArray();
toString()	Returns the string itself.	String	str.toString();