Syntax: for start test next command

The for command provides a C-like "for" loop, where start is a script that initializes the loop counter, test is a conditional expression, next is a script that updates the loop counter, and command is the body script.

If the command script calls the break command, the loop terminates immediately; if the command script calls the continue command, loop execution continues with the next iteration.

For example, the following loop counts from 0 to 9:

for {set i 0} {$i < 10} {incr i} {
    puts "i=$i"
}

Note, though, that the start and next arguments are arbitrary scripts; for example, start can initialize multiple variables, and next can update multiple variables.