The
loop construct found in nearly all
procedural languages which executes one or more instructions
(the "loop body") repeatedly so long as some
condition
evaluates to true. In contrast to a
repeat loop, the loop
body will not be executed at all if the condition is false on
entry to the while.
For example, in
C, a while loop is written
while (<expr>) <statement>;
where <expr> is any expression and <statement> is any
statement, including a compound statement within braces
"..".