arithmetic

procedure

for & foreach functions

>set a 1

1

>set b a

a

>set b $a

1

>expr 2 + 3

5

>expr 2 + $a

3

>set b [expr 2 + $a]

3

>

>proc sum {a b} {

return [expr $a + $b]

}

>sum 2 3

5

>set c [sum 2 3]

5

>

for {set i 1} {$i < 10} {incr i 1} {

puts "i equals $i"

}

set sum 0

foreach value {1 2 3 4} {

set sum [expr $sum + $value]

}

puts $sum

10

>

file manipulation

procedure & if statement

>set fileId [open tmp w]

anumber

>puts $fileId "hello"

>close $fileID

>type tmp

hello

>

>source Example1.tcl

>proc guess {value} {

global sum

if {$value < $sum} {

puts "too low"

} else {

if {$value > $sum} {

puts "too high"

} else { puts "you got it!"}

}

}

> guess 9

too low

>