I would maintain that conditional behavior is the key element that makes a computer a computer. Conditional behavior is implemented at the machine level by operations such as BEQ XYZ (branch to instruction XYZ) and at high?level language level by operations such as IF x == y then do THIS else do THAT. Why are such conditional operations so necessary to computing?

Question

What will be an ideal response?

Answer 1

Without conditional behaviour, each program would consist of a sequence of operations that were always executed in the same way every time the program was run. For example; you could build a computer to evaluate ? to 50 decimal places by using a sequence of arithmetic operations without conditional operations.

Conditional operations allow a computer to change the sequence of operations it will execute, according to the outcome of a test. For example, when simulating a game of chess, a computer may first move each chess piece onto a different square and then evaluate the goodness or figure of merit of that position. That calculation can be done without conditional behavior. Suppose at a given stage of play there are seven possible moves, and the figures of merit of the moves are 2, ?3, ?10, 20, 1, 0, 9 with the highest number signifying the best. In this case the computer would select the move with the figure of merit 20 as best and then continue from that point. It is this conditional behavior that gives the computer its great power.