Example 7: Summation Of Same Index Elements Of Two Different Lists

#!/usr/bin/tclsh

puts "Enter values of List A: "
gets stdin listA

puts "Enter values of List B: "
gets stdin listB

proc add_list {a b} {
	set c {}
	if { [llength $a] != [llength $b]} {
		puts "\nList Length Is Not Equal. Try Again!"
	} else {
		foreach i $a j $b {
			lappend c [ expr $i + $j]
		}
		puts "\nSummation of {$a} and {$b} is {$c}"
	}
}

add_list $listA $listB

Output:

Enter values of List A:
1 2 3 4 5
Enter values of List B:
1 2 3 4 5

Summation of {1 2 3 4 5} and {1 2 3 4 5} is {2 4 6 8 10}

Enter values of List A:
1 2 3 4 5
Enter values of List B:
1 2 3 4

List Length Is Not Equal. Try Again!