While...Wend statement - MapBasic - 2023

Purpose

Defines a loop which executes as long as a specified condition evaluates as TRUE.

Syntax

While condition 
	 statement_list 
Wend

condition is a conditional expression which controls when the loop should stop.

statement_list is the group of statements to execute with each iteration of the loop.

Restrictions

You cannot issue a While...Wend statement through the MapBasic window.

Description

The While...Wend statement provides loop control. MapBasic evaluates the condition; if it is TRUE, MapBasic will execute the statement_list (and then evaluate the condition again, etc.).

As long as the condition remains TRUE, MapBasic will repeatedly execute the statement_list. When and if the condition becomes FALSE, MapBasic will skip the statement_list, and continue execution with the first statement following the Wend keyword.

Note that a statement of this form:

While condition 
	 statement_list 
Wend

is functionally identical to a statement of this form:

Do While condition 
	 statement_list 
Loop 

The While...Wend syntax is provided for stylistic reasons (for example, for the sake of those programmers who prefer the While...Wend syntax over the Do...Loop statement syntax).

Example

Dim psum As Float, i As Integer
Open Table "world"
Fetch First From world
i = 1
While i <= 10
	psum = psum + world.population
	Fetch Next From world
	i = i + 1 
Wend

See Also:

Do...Loop statement, For...Next statement