Java string methods list

Whitney 95 Published: 07/06/2024

Java string methods list

Here is a comprehensive list of Java string methods:

String Manipulation Methods

toString(): Returns the string representation of an object. valueOf(String s): Returns the string value equivalent to the specified Object. format(String format, Object... args): Formats the string using the specified format and arguments. concat(String str): Returns a new string that is a concatenation of this string and the specified string. substring(int beginIndex): Returns a new string that is a substring of this string starting at the specified index.

Searching Methods

indexOf(String str, int fromIndex): Returns the position within this string where the specified string begins. lastIndexOf(String str, int fromIndex): Returns the position within this string where the specified string begins. contains(String str): Indicates whether or not this string contains the specified sequence of character(s). startsWith(String prefix): Tests if this string starts with the given prefix.

Replacing Methods

replace(char oldChar, char newChar): Replaces each substring of this string that matches the given regular expression replacement. replaceAll(String regex, String replacement): Replaces each substring of this string that matches the given regular expression replacement. replaceFirst(String regex, String replacement): Replaces the first occurrence of a substring that begins with the specified prefix.

Splitting and Joining Methods

split(String regex): Splits this string around matched whitespace using the given regular expression. join(CharSequence separator, CharSequence... elements): Concatenates all the elements in the specified array into a single string.

Other Methods

trim(): Returns a string where all leading and trailing characters are removed. toLowerCase(): Converts this string to lowercase using the platform's default locale. toUpperCase(): Converts this string to uppercase using the platform's default locale. length(): Returns the length of the string. charAt(int index): Returns the character at the specified position in the string. equals(String s): Compares two strings for their lexical order.

This is not an exhaustive list, as there are many more Java string methods available. However, this should give you a good starting point and provide insight into some of the most commonly used string manipulation methods in Java.

Java string methods w3schools

Here are the Java String methods from W3Schools:

Methods for Creating a New String:

concat(): Concatenates two strings. 
String str = "Hello";

str = str.concat(", World");


System.out.println(str);
format(): Formats a string with variables. 
String str = String.format("Hello, %s!", "World");

System.out.println(str);
intern(): Returns a canonical representation for the string.

Methods for Modifying a String:

charAt(): Returns the character at a specified index. 
String str = "Hello";

char c = str.charAt(0);


System.out.println(c);
codePointAt(): Returns the Unicode code point of a character at a specified index. 
String str = "Hello";

int cp = str.codePointAt(0);


System.out.println(cp);
concat(): Concatenates two strings. 
String str = "Hello";

str = str.concat(", World");


System.out.println(str);
endsWith(): Checks if a string ends with a specified suffix. 
String str = "Hello";

boolean result = str.endsWith("o");


System.out.println(result);
equals(): Compares two strings for equality. 
String str1 = "Hello";

String str2 = "Hello";


boolean result = str1.equals(str2);


System.out.println(result);
equalsIgnoreCase(): Compares two strings regardless of case. 
String str1 = "Hello";

String str2 = "hello";


boolean result = str1.equalsIgnoreCase(str2);


System.out.println(result);
indexOf(): Searches for a specified character or substring in a string. 
String str = "Hello";

int index = str.indexOf("o");


System.out.println(index);
lastIndexOf(): Returns the index of the last occurrence of a specified substring. 
String str = "Hello";

int index = str.lastIndexOf("o");


System.out.println(index);
length(): Returns the length of a string. 
String str = "Hello";

int length = str.length();


System.out.println(length);
replace(): Replaces a specified substring with another string. 
String str = "Hello, World!";

str = str.replace("World", "Java");


System.out.println(str);
replaceFirst(): Replaces the first occurrence of a specified pattern. 
String str = "Hello, World!";

str = str.replaceFirst(", ", "- ");


System.out.println(str);
split(): Splits a string into multiple strings based on a specified delimiter. 
String str = "Hello, World!, Java!";

String[] array = str.split(",");


for (int i = 0; i < array.length; i++) {


System.out.println(array[i]);


}
startsWith(): Checks if a string starts with a specified prefix. 
String str = "Hello";

boolean result = str.startsWith("He");


System.out.println(result);
subSequence(): Returns a new string that is a subset of the original string. 
String str = "Hello";

int start = 0;


int end = 3;


String sub = str.subSequence(start, end).toString();


System.out.println(sub);
substring(): Returns a substring from a specified starting index to a specified ending index. 
String str = "Hello";

int start = 1;


int end = 4;


String sub = str.substring(start, end);


System.out.println(sub);
toCharArray(): Converts a string into an array of characters. 
String str = "Hello";

char[] charArray = str.toCharArray();


for (int i = 0; i < charArray.length; i++) {


System.out.println(charArray[i]);


}
toLowerCase(): Converts a string to lowercase. 
String str = "HELLO";

str = str.toLowerCase();


System.out.println(str);
toString(): Returns the string representation of an object.

Methods for Searching in a String:

contains(): Checks if a string contains a specified substring. 
String str = "Hello, World!";

boolean result = str.contains("World");


System.out.println(result);
endsWith(): Checks if a string ends with a specified suffix. 
String str = "Hello";

boolean result = str.endsWith("o");


System.out.println(result);
indexOf(): Searches for a specified character or substring in a string. 
String str = "Hello";

int index = str.indexOf("o");


System.out.println(index);
lastIndexOf(): Returns the index of the last occurrence of a specified substring. 
String str = "Hello";

int index = str.lastIndexOf("o");


System.out.println(index);
regionMatches(): Compares two strings within a specified range. 
String str1 = "Hello";

String str2 = "Hallo";


boolean result = str1.regionMatches(0, str2, 0, 4);


System.out.println(result);
search(): Searches for a specified pattern in a string.

Methods for Modifying the Case of a String:

toLowerCase(): Converts a string to lowercase. 
String str = "HELLO";

str = str.toLowerCase();


System.out.println(str);
toUpperCase(): Converts a string to uppercase. 
String str = "hello";

str = str.toUpperCase();


System.out.println(str);
toTitleCase(): Converts the first character of each word in a string to uppercase.

I hope this helps! Let me know if you have any questions or need further clarification on any of these methods.

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