[!INDEX]

1. Exception flow ( 7 points ).
2. arithmetic ex. Handling Using try-catch ( div/0 )
3. code flow + try-catch + rest code + no error ( 1 to 7 code )
4. code flow + arithmetic ex. + try-catch + rest code + error ( above code )
5. method of ex. object printing( 4 way )
6. only try block
7. cH block only
8. fn/y block only
9. 1 tR multiple cH, same eX type
10. 1 tR multiple cH, parent-chid eX.
11. 1 tR multiple cH, chid-parent eX.

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1. Exception flow ( 7 points )

[!important]

1. जैसे ही exception मिलेगा concern method एक object बनायेगा और JVM को पास कर देगा |
2. this object has three parts -
3. exception name ,
4. description and
5. stack trace
6. JVM चेक करेगा की यह exception - handle हो रहा है की नही |
7. अगर नही तो JVM , exception object को डिफ़ॉल्ट एक्सेप्शन हैंडलर ( DEH ) को दे देगा |
8. लेकिन उससे पहले JVM प्रोग्राम को abnormally terminate कर देगा |
9. और ( DEH ) उसको प्रिंट करवा देगा |
10. उससे बचने के लीये exception को manually handle करना पड़ेगा |

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2. Manual Handling + try-catch + arithmetic exception + error .

public class L02 { 
    public static void main(String[] args) { 
        try{ 
            int a=100, b=0, c; 
            c=a/b; 
            System.out.println(c); 
        } 
        catch(Exception e){ // if dont know the excat exception, use excepion , it will pass it to arithmatic exception
            System.out.println(e); // e = exception object name
            System.out.println("error in the code, pls check"); 
        } 
            System.out.println("Program ends Here"); 
    } 
}

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3. code flow + try-catch + rest code + no error ( 1 to 7 code )

package package2;
public class Main1 {
    public static void main(String[] args) {
        System.out.println("1");
        try{
            System.out.println("2");            
            int a=100, b=2, c;
            System.out.println("3");
            c=a/b;
            System.out.println("4");
            System.out.println(c);
            System.out.println("5");
        }
        catch(ArithmeticException e){ // skiped block
            System.out.println("6");
            System.out.println(e);
            System.out.println("7");            
        }
        System.out.println("normal flow");
    }
}

1
2
3
4
50
5
normal flow

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4. code flow + arithmetic ex. + try-catch + rest code + error ( above code )

package package2;
    public class Main1 {
        public static void main(String[] args) {
            System.out.println("1");
            try{
                System.out.println("2");            
                int a=100, b=0, c;
                System.out.println("3");
                c=a/b;
                System.out.println("4");
                System.out.println(c);
                System.out.println("5");
            }catch(ArithmeticException e){
                System.out.println("6");
                System.out.println(e);
                System.out.println("7");            
            }
            System.out.println("normal flow");
        }
    }

1
2
3
6
java.lang.ArithmeticException: / by zero
7
normal flow

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5. method of ex. object printing( 4 way )

package package2;
public class Main1 {  
    public static void main(String[] args) {
        try{
            int a=100, b=0, c;
            c=a/b;
            System.out.println(c);
        }catch(ArithmeticException e){
            /* whole description */
            e.printStackTrace();
            /* blow both same - exception name and description */            
            System.out.println(e);
            System.out.println(e.toString());
            /* only message */          
            System.out.println(e.getMessage());  
        }
    }
}

java.lang.ArithmeticException: / by zero
        at package2.Main1.main(Main1.java:6)
e = java.lang.ArithmeticException: / by zero
toString = java.lang.ArithmeticException: / by zero
getMessage = / by zero

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6. only try block

package package2;
public class Main1 {  
    public static void main(String[] args) {
        try{
            // only try block
        }
    }
}

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7. cH block only

package package2;
public class Main1 {  
    public static void main(String[] args) {
        catch(Exception e){
            // error: 'catch' without 'try
        }
    }
}

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8. fn/y block only

package package2;
public class Main1 {   
    public static void main(String[] args) {
        finally{
            // error: 'finally' without 'try'
        }
    }
}

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9. 1 tR multiple cH, same eX type

package package2;
public class Main1 {  
    public static void main(String[] args) {
        try{

        }catch(Exception e){

        }catch(Exception e){

            // error: exception Exception has already been caught
        }
    }
}

Unreachable catch block for Exception. It is already handled by the catch block for ExceptionJava(553648315)

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10. 1 tR multiple cH, parent-child eX

package package2;
public class Main1 {  
    public static void main(String[] args) {
        try{
        }catch(Exception e){
        }catch(ArithmeticException e){
            // exception ArithmeticException has already been caught
        }
    }
}

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11. 1 tR multiple cH, chid-parent eX

package package2;
public class Main1 {  
    public static void main(String[] args) {
        try{
        }catch(ArithmeticException e){
        }catch(Exception e){
            // works fine
        }
    }
}

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