Strings in Java

Strings in Java

Transcript

1. JAVA PROGRAMMING TOPIC: STRINGS IN JAVA -MAYURI M. VATHARE
2. STRINGS • Strings is group of Characters enclosed in single or double quote. • String is an immutable(not allowed Modification) • for each modification on the string object it creates separate objects in the memory • String concept is also thread safe bcz we can’t modify the object. • if we try to modify a new object will create so all immutable objects are thread safe (even wrapper classes) . • Example: String s="Java";
3. EXAMPLES public class StringDemoS { public static void main(String[] args) { String s="Java"; System.out.println(s); s.concat("Programming"); System.out.println(s); s.concat("Language"); System.out.println(s); } } Output: Java Java Java
4. EXPLANATION String s=new String(“Java”); Syso(s); Java s.concat(“Programming”); Syso(s); Java Programming s.concat(“Language”); Syso(s); Java Language
5. WAYS TO CREATE STRINGS There are two ways to create String in Java 1.String Literal Approach 2.Creating Object
6. STRING LITERAL APPROCH String s1="JAVA"; String s2="java"; String s3="JAVA PROGRAM";
7. CREATING OBJECT Syntax:String s = new String (); Example: • String s4=new String("JAVA"); • String s = new String (“welcome); • String s = new String (“welcome”); String s1 = new String (s);
8. CONSTANT POOL • It is a section available in Heap Memory. • It only store object of String which has been created using String Literal. • Never accept duplicate String Object. • If we try to create duplicate Object of String instead of creating new one it provide only object Reference.
9. Heap Memory Constant Pool Riya riya
10. Heap Memory Example Constant Pool Riya riya Riya riya Riya
11. EXAMPLE public class StringDemo { public static void main(String[] args) { String s1=new String (“You are best”); String s2=new String (“You Are best”); System.out.println(s1==s2); → false String s3= “You are best”; System.out.println(s1==s3); → false String s4= “You are best”; System.out.println(s3==s4); → true } }
12. Important Methods Of String • public char charAt(int index) • public char charAt(int index) Example:String s= “adah”; System.out.println(s.equals(“Adah”)); → false • concat(String s) String s= “adah”; s=s.concat(“student”); System.out.println(s); → Java Programming
13. THANK YOU