Java Strings: Conversing with Computers

Stumbling upon the mysterious world of computers and coding would initially make learners feel intimidated. The journey starts with writing a code to print a simple ‘hello world,’ but there is absolutely no telling where this journey can lead you. Amongst various coding languages like C, C++, and Python, the most popular is Java. Let’s take a look at one of the integral concepts involved in Java: Java Strings.

Java holds a special place in the computing paradigm as it is used by both amateurs and experts to build anything from simple academic projects to complex corporate systems. Learning Java can be highly rewarding to those new to coding as it is simple and flexible. 

A. What Is A Java String?

In layman’s terms, a string is nothing but a sequence of characters, i.e., “ABC,” “hello,” etc. But Java is an object-oriented language, which means that Java’s different aspects and functionalities are treated as specific objects. Similarly, a Java String represents a particular sequence of characters that can be created using a Java String class called the java.lang.String. 

B. Properties And Operations Of Java Strings

Java Strings are widely used during programming. One of their crucial properties is that they are immutable. Immutable strings, once defined in a code, cannot be modified further. Even if you perform Java String functions like concatenation on an existing string, the string will not change. Instead, a new object string will be created to display the modifications.

Speaking of functions, let’s discuss some Java String concepts in brief. There are various Java String functions examples that amateurs can try out as well. For instance, Java String Concatenation allows you to create a new string by combining two or more existing strings.

Using the Java String Comparison function, you can check whether two strings are equal in value or not. The result of such Java String operations is usually in boolean values i.e., true or false. You can also obtain a subset of an existing string using the Java Substring operation. The basis for solving Java String problems lies in understanding Java String syntax and Java String format. Every Java String type is basically a variant created using various methods.

Let’s look at some Java String examples to understand how Java String related programs work.

1. Creating a Java String 

You can create a Java String using two Java String Initialization methods viz. Direct Initialization and Object Initialization. The latter is preferable in most cases as it has a more dynamic approach. Below is an example of the same.

Input:

public class StringDemo1 {

   public static void main(String args[]) {

      char[] welcomeArray = { ‘w’, ‘e’, ‘l’, ‘c’, ‘o’, ‘m’, ‘e’, ‘!’ };

      String welcomeString = new String(welcomeArray);  

      System.out.println( welcomeString );

   }

}

Output: welcome!

2. Java String Concatenate

This method appends one string to the end of another. It returns a new String object with the value of the second string concatenated to the end of the first string.

Input:

public class StringDemo2 {

   public static void main(String args[]) {

      String s1 = “helped me “;

      System.out.println(“Tom ” + s1 + “dance”);

   }

}

Output: Tom helped me dance

3. Java String Compare 

There are three approaches to comparing Java Strings viz. Using ‘equals()’ method, ‘==’ operator or ‘compareTo()’ method. The first two methods return a boolean type value of true or false. Whereas the compareTo method will return one of the following three values: ‘0’ if both strings are equal, ‘negative value’ if the first string is smaller than the second string, and ‘positive’ value in the case of the first string being greater than the second.

Input:

class Demostringcomparison{  

 public static void main(String args[]){  

   String string1=”Hey”;  

   String string2=”Hey”;  

   String string3=new String(“Hey”);  

   String string4=”Hi”;  

   System.out.println(s1.equals(s2));  

   System.out.println(s1.equals(s3));  

   System.out.println(s1.equals(s4));  

 }  

}  

Output: true

               true

               false

4. Substring Java String

Java String Substring method has two variants, both of which return a new string that is a subset of the original string. The difference in the two variants is that one allows you to specify the starting point of the substring and then runs to the very end, and the other allows you to specify the starting and ending point of the substring. We have elaborated both variants in the following example.

Input:

public class DemoSubstring{  

 public static void main(String args[]){  

   String s=”RameshJha”;  

   System.out.println(s.substring(6));  

   System.out.println(s.substring(0,6));  

 }  

}  

Output:

Jha

Ramesh

5. Java String Split

The string split() method cuts the given string at the character specified by the user, and returns split parts separately.

Input:

public class SplitTest{  

public static void main(String args[]){  

String s1=”This is how you split”;  

String[] words=s1.split(“\\s”);   

for(String w:words){  

System.out.println(w);  

}  

}}  

Output:

This

is

how 

you

split

6. Java String Length

This method allows you to pass a string object and returns the number of characters present in it. It only works with string objects.

Input:

public class StringDemo {

  public static void main(String args[]) {

      String palindrome = “Tom ran after jerry”;

      int len = palindrome.length();

      System.out.println( “String Length is : ” + len );

   }

}

Output: String Length is: 1

7. Java String to CharArray

The toCharArray() method creates an array of characters that is the same length as the given string. It then returns the characters in the string in the new character array.

Input:

public class StringToCharArrayExample{  

public static void main(String args[]){  

String s1=”hello”;  

char[] ch=s1.toCharArray();  

for(int i=0;i<ch.length;i++){  

System.out.print(ch[i]);  

}  

}} 

Output: hello

Conclusion

In this article, we discussed Java Strings and also explained various Java String methods available. There are many other Java String programs for you to explore, like Java String-list. Simple Java String programs are just the beginning of your adventure in the world of coding and computers. To experience this journey to the fullest, the Master Certificate In Full Stack Development offered by Jigsaw Academy is perfect for you. This online instructor-led program runs for 170 hours and extensively covers Full Stack Development with Automation and AWS Cloud.

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