Syntax:
while expr
[statementBlock]
wend
Description:
The while
statement marks the beginning of a "while-loop," which must end with a wend
statement. statementBlock
consists of zero or more executable statements, possibly including other while-loops. When a while
statement is encountered, FutureBasic evaluates expr
. If expr
is nonzero, FutureBasic executes the statements in statementBlock
; otherwise it jumps down to the first statement following wend
.
If the statementBlock
statements are executed, the process is repeated; expr
is evaluated again, and if it's still nonzero, the statementBlock
statements are executed again. This loop continues until expr
becomes zero, at which point the program exits the loop and jumps down to the first statement following wend
.
Typically, expr
is an expression involving logical operators, which is evalutated either as _zTrue
(-1) or as _false
(0). See the If statement for more information about expr
.
Note that if expr
is zero the first time it's evaluated, the statements in statementBlock
are not executed at all.
do...until
is an alternative loop structure that executes statementBlock
at least once.
See Also:
for...next; do...until; If