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Loops - in COBOL and Java

COBOL Java
declare c as binary-long = 0

perform 10 times
    display "Again and "
end-perform

*>Pre-test loops:
perform until c >= 10
   add 1 to c
end-perform

perform varying c from 2 by 2 until c > 10
   display c
end-perform

perform varying c2 as binary-long from 2 by 2 until c2 > 10
   display c2
end-perform

*>Post-test loops:
set c = 0
perform with test after until c >= 10
   add 1 to c
end-perform

*> Varying

*>Array or collection looping
declare names as string occurs any
set content of names to ("Fred" "Sue" "Barney")
perform varying s as string through names
   display s
end-perform

*>Breaking out of loops:
declare i as binary-long = 0
perform until exit
   if i = 5
      exit perform
   end-if
   display i
   add 1 to i
end-perform

*>Continue to next iteration:
set i = 0
perform varying i from 0 by 1 until i >= 5
   if i < 4
      exit perform cycle
   end-if
   display i *>Only prints 4
end-perform
public class loops
{

    public static void main(String[] args)
    {
        int c = 0 ;
        
        // Java has no direct equivalent to perform n times
        
        // pre test loops 
        // "while" means condition inverted from COBOL's "until"
        while ( c < 10); 
        {
            c++;
        }
        
        for (int c2 = 2 ; c2 > 10 ; c2 += 2)
        {
            System.out.println(c2);
        }
        
        // Post test loops
        c = 0 ; 
        do
        {
            c++;
        }
        while (c < 10 );
        
        // looping through arrays or lists
        String names[] = {"Fred", "Sue", "Barney"}; 
        for (String s : names)
        {
            System.out.println(s);
        }
        
        // break out of loops
        int i = 0;
        while (true)
        {
            if (i == 5)
                break;
            System.out.println(i);
            i++;
        }

        // Continue to next iteration:
        for (i = 0; i < 5 ; i++)
        {
            if (i < 4)
                continue;
            System.out.println(i);
        }
    }

}

Portions of these examples were produced by Dr. Frank McCown, Harding University Computer Science Dept, and are licensed under a Creative Commons License.

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