Java has approximately 5000 packages. Each package contains many classes. Java.lang is an important package that comes with Java. This package is automatically included in every program you write. String is an important class in this package. It would take a whole day to explain the string class so we will only discuss the basics of string. This includes how to declare strings and how to use them in our Java code.
You are probably familiar with a few programming languages, other than Java, and you know that some languages implement strings in character arrays. Java is different. Java implements strings using objects of type String (the class found in the java.lang package). This feature allows programmers to easily work with strings. You can also create a string object in many different ways. To validate your Java skills, you can also obtain a Java programming certification.
String objects in Java are unique because once they are created, you can’t change them. As you can see, you cannot alter the characters that compromise a string. Java provides an alternative solution for any restrictions it places on a string.
Java states that you cannot modify the string object. However, you can still modify it. There are many ways to create a string object, and declare it. For now, however, we will use the simplest method to declare the string. String S= “Hello”, The string literal is used to represent the string object created in the previous statement. S is the reference variable.
How to Modify a String
We have already discussed that strings cannot be modified once they are created. To modify strings, we use the following methods: 1) substring(): This method allows you to extract a portion of an originally declared string/string object. This method can be used in one of two ways:-a. String substring(int beginIndex): You use the startIndex to specify the index where your modified string should start. Your new string will start at the specified index number and run to the end. Consider, for example, a string that is declared as String S=”conversion”, and String S1=S.substring(2). This gives us S1 as “nversion”.b String substring(int beginIndex, int endingIndex): This method allows you to specify the starting point and the end of the new string. String S2= S.substring(2); this gives us S2=”nve”.
You can also learn more about casting in Java
2) concat(): This function allows you to concatenate two strings. This means that concat() can be used to combine the strings. This function can be used to add characters to an existing string. This function can be used to add characters to a string such as String S1=”Hello” and String S2=S1.concat()(“Everyone ” This will give you S2’s value as “Hello everyone”.
3) replace() : This method modifies the original string by replacing certain characters. There are two ways to replace characters: a) String replace(char initial, char replacement); This replaces only one character from the original string. For example, String S=”Hello”.replace(‘e’, ‘x’); gives us Hwllo as the value of S.b) String replace(CharSequence original, CharSequence replacement): Unlike the above method, which replaces only one character at a time, using this method you can replace a sequence of characters in one go. String S=”He’s a good boy” replace(“good”, ‘bad”); gives us an output. He’s a bad boy.
4) Trim(): Sometimes, you might leave extra spaces at the beginning or end of your original string. These strings can look strange when printed. These strings cannot be changed in value, but you can modify them by removing the white spaces. You can declare a string by writing String S1=”Hey, brown cow”, which has a lot of white space at the beginning and end. You can use the trim function to improve it. String S2=S1.trim() can be used to remove any white spaces.
To conclude, I would like to point out that Java has provided four methods to modify the original string declared by Java. Start your Java development journey by learning the Ja
