Question

I’m trying to create a program that the First and last characters are compared, Second and second to the last are compared, Third and third to the last are compared, and so on, and if any of these characters match, the two will be converted to the uppercase of that character.

Example:

Please enter a text: Hello Philippines
finals: HEllo PhIlippinEs

I can’t create any piece of code, I’m stuck with

puts "Please enter text:"
set myText [gets stdin]

string index $myText 4 

Can someone help me please?

Answer 1

This procedure will also capitalize the first i in Phillipines because it’s equidistant from the start and the end of the string.

proc compare_chars {str} {
    set letters [split $str ""]
    for {set i [expr {[llength $letters] / 2}]} {$i >= 0} {incr i -1} {
        set a [lindex $letters $i]
        set b [lindex $letters end-$i]
        if {$a eq $b} {
            lset letters $i [set L [string toupper $a]]
            lset letters end-$i $L
        }
    }
    join $letters ""
}
puts [compare_chars "Hello Phillipines"]
# outputs =>  HEllo PhIllipinEs