The ELSE statement optionally follows the IF statement and gives an action to be taken when the IF expression is false. The expression to be evaluated is often a comparison, for example, if max (a)<20 ...

The IF statement results in the evaluation of the condition (MAX (A)<20). If the largest value found in matrix A is less than 20, P is set to 0. Otherwise, P is set to 1. You can nest IF statements ...