Kinds of Loops in Visual Basic

In programming, loops are a very essential piece of any program. All loops have the same basic functionality, as they all continue to execute a set block of code until a certain condition is reached. Some loops are better-suited for certain situations, although most of the time it is just programmer preference. Most applications of a particular loop can usually be achieved by using any of the other loops with the correct syntax.

For Loops

"For" loops are one of the most widely used loops in programming. A "For" loop is designed to execute a set of code a predetermined number of times before being terminated. A loop index is needed to hold the count for each run of the loop. Once the loop reaches its limit, it is terminated, and the next batch of code is executed.

While Loops

"While" loops continue executing a set of commands until a specified condition is reached. For example, this type of loop will continue executing while the variable is less than four. Once the variable is set to something higher than three, the loop will finish its course.

Do Until Loops

"Do Until" loops are used when code needs to continue to be executed until a condition is met. An example of a "Do Until" loop would be to keep executing commands until the variable is false. Once the variable is switched from true to false, the loop will be terminated. This loop offers an "Exit Do" command to exit the loop prior to it reaching the specified condition.

Do While Loops

"Do While" loops execute code while a particular condition remains true. For example, this type of loop will execute specific code while variable one is greater than variable two. The code will continue to be executed until variable two becomes greater than variable one. This loop also is able to use the "Exit Do" statement.

References

• Loops in VB.NET: For Loop, While Loop, Do Loop