Selection
In programming, there are occasions when a decision needs to be made. A decision within a computer program when the program decides to move on based on the results of an event. is the process of making a decision. The result of the decision determines which path the A sequence of logical instructions for carrying out a task. In computing, algorithms are needed to design computer programs. will take next.
For example, an algorithm could tell a user whether they are old enough to learn how to drive a car. If the user's age meets the required driving age, the program would follow one path and The process of a program being run on a computer. one set of A single action that can be performed by a computer processor.. Otherwise, it would follow a different path and execute a different set of instructions.
An explanation of selection, as used in algorithms and programming
Selection works by testing a In computing, this is a statement that is either true or false. A computation depends on whether a condition equates to true or false.. The test gives a A data type in computing which only has two possible values, true or false. result – TRUE or FALSE, YES or NO, 1 or 0. In the next example, if the result is YES, the program follows one path, otherwise it follows another.
In Also written as pseudo-code. A method of writing up a set of instructions for a computer program using plain English. This is a good way of planning a program before coding., selection is implemented using if else end ifThe smallest element of a programming language which expresses an action to be carried out.:
age is integer input “How old are you?”, age if age >= 17 output “You are old enough to drive a car!” else output “Come back when you are older!” end ifIn the above pseudocode program, the path the program takes depends on the condition. A A memory location within a computer program where values are stored., in this case age, is used to test the condition.
If the value of age is 17 or more, the result of the tested condition is YES and the program follows the first path, which informs the user that they are old enough to drive.
If the value of age is 16 or under, the result is NO and the program follows the second path, which follows the statement else. This path informs the user that they are not yet old enough to drive.
The statement end if ends the selection.
