Strings In Java
Java Strings are discussed, to better meet the demands of the learners.
Java Strings
A string is used to store text. It consists of a collection of characters surrounded by double quotes.
Assign a value to a String variable:
Example:
public class Main{
public static void main(String[] args) {
String mrx_name="We are learning about Java Strings ";System.out.println("Text = "+mrx_name);}
// Output = Text = We are learning about Java Strings
};
Another Example:
public class Main{
public static void main(String[] args) {
String ample_text="Hey Everyone !!";
String mrx_name=" We are learning about Java Strings ";System.out.println(ample_text+mrx_name);}// Output = Hey Everyone !! We are learning about Java Strings
};
Table Of Content-
String Length
Java strings are actually objects that contain methods to perform certain operations on strings.
A string’s length can be found with the length() method, for instance:
Example:
public class Main{
public static void main(String[] args) {
String mrx_name="We are counting the length of the string using length() method ";
System.out.println("length of String= "+mrx_name.length());}// Output = length of String= 60
};
Example:
public class Main{
public static void main(String[] args) {
String mrx_name="12345678910";
System.out.println("length of String= "+mrx_name.length());}// Output = length of String= 11
};
More String Methods
There are a variety of methods in String, for example toUpperCase() and toLowerCase():
Example:
public class Main{
public static void main(String[] args) {
String mrx_name="We are learning toUpperCase and toLowerCase methods of String ";
System.out.println("Uppercase: "+mrx_name.toUpperCase());
System.out.println("Lowercase: "+mrx_name.toLowerCase());}// Output 1 = Uppercase: WE ARE LEARNING TOUPPERCASE AND TOLOWERCASE METHODS OF STRING
// Output 2= Lowercase: we are learning touppercase and tolowercase methods of string
};
Another Example:
public class Main{
public static void main(String[] args) {
String mrx_name="Java is an object oriented programming language";
System.out.println("Uppercase: "+mrx_name.toUpperCase());
System.out.println("Lowercase: "+mrx_name.toLowerCase());}// Output 1 = Uppercase: JAVA IS AN OBJECT ORIENTED PROGRAMMING LANGUAGE
// Output 2= Lowercase: java is an object oriented programming language
};
Java Strings Character Search
The indexOf() method returns the position of the first instance of a specified text in a string (including whitespace) along with the index (the number) at which it appears:
Example:
public class Main{
public static void main(String[] args) {
String txt = "Return index of word Java !";
System.out.println("Index number= "+txt.indexOf("Java")); //}// Output: Index number= 21
};
Example:
public class Main{
public static void main(String[] args) {
String txt = "1 2 3 4 5 6 7 8 9 ";
System.out.println("Index number of 6 = "+txt.indexOf("6")); //}// Output: Index number of 6 = 10
};
Java starts counting locations from zero.
A string’s initial position is 0, its second is 1, and its third place is 2.
Java Strings Methods
| Methods | Overview |
|---|---|
| contains() | Checks if a substring exists in the string. |
| substring() | Substrings of strings are returned. |
| join() | Strings are joined using the delimiter. |
| replace() | Specifies a new character to replace the old one. |
| replaceAll() | Substrings matching a regex pattern are replaced. |
| replaceFirst() | First matching substring should be replaced. |
| charAt() | The character present in the specified location will be returned. |
| getBytes() | Bytes are converted from the string. |
| indexOf() | In a string, this function returns the position of the specified character. |
| compareTo() | The dictionary order is used to compare two strings. |
| compareToIgnoreCase() | Case differences are ignored when comparing two strings. |
| trim() | Removes all leading and trailing whitespaces. |
| format() | A formatted string is returned. |
| split() | Divides a string into an array. |
| toLowerCase() | Lowercases the string. |
| toUpperCase() | Uppercases the string |
| valueOf() | The specified argument will be returned as a string. |
| toCharArray() | This function converts the string into a char array. |
| matches() | Matches the string against the regex.. |
| startsWith() | This method checks if a string begins with a given string. |
| endsWith() | A string is checked to see if it ends with the given string. |
| isEmpty() | An empty string is checked or not. |
| intern() | This function returns the string’s canonical representation. |
| contentEquals() | A string is compared to charSequence to determine if it is equal |
| hashCode() | The string’s hash code is returned. |
| subSequence() | The string is subsequenced by this method. |
Visit our Java String Methods Reference for a comprehensive list of String methods.
All string methods are covered in the reference, along with descriptions and examples.
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