LabVIEW For Loops and While Loops Explained

A While Loop is a structure you use to execute a block of LabVIEW code repeatedly until a given condition is met. When the VI runs, the code inside the While Loop executes, and then the terminal condition is evaluated. The While Loop will be a familiar concept for experienced programmers as it operates similarly in other computer languages.

LabVIEW While Loop flowchart

Unlike a For Loop, While Loop execution does not depend on iteration count; thus, a While Loop executes indefinitely if the condition never occurs.

For more information on what a While Loop is, including its components and configuration options, look into While Loops in LabVIEW Help.

A For Loop is a structure you use to execute a block of code a set number of times. When the VI runs, the iteration count is evaluated, and then the code is executed.

LabVIEW For Loop flowchart

A For Loop can be configured to conditionally stop code execution in addition to its iteration-based exit. In these cases, the code will execute until the count terminal setting is reached or the condition is met – whichever happens first.

While Loops should be used when:

• You want your code to run indefinitely
• You want to run code until a condition is met
• You want user control over when code should stop
   

For Loops should be used when:

• You need to run code for a certain number of times
• You want to write a set number of measurements to a file
• You want to take a certain number of data points
• You want to run code until a condition is met OR a set number of iterations, whichever comes first

• Build and Configure a While Loop in LabVIEW
• Build and Configure a For Loop in LabVIEW

• Learn NI LabVIEW Basics – LabVIEW Getting Started
• While Loop – LabVIEW Help
• For Loop – LabVIEW Help
• Improving Performance with Parallel For Loops in LabVIEW
• Stopping Parallel While Loops in LabVIEW with One Stop Button