Java

4.2    The Extended for Loop

for loops often traverse arrays or data structures. As earlier in Section 4.1.6 , when calculating the mean value, we can use the following code:

                
            double sum = 0;for ( int 
            i = 0; 
            i < numbers.length; 
            i++ )  sum += numbers[ 
            i ];double arg = sum / numbers.length; 

The only justification for the loop variable i is to serve as an index; only with i can the element be addressed at a certain place in the array.

Because complete iterations of arrays are frequent, the following shortcut can be used for such iterations:

for ( 
            type identifier: 
            Array )  … 

The extended form of the for loop detaches from the index and queries each element of the array. Think of this as passing through a set because the colon can be read ...