# Tcl 8.4

Version of implementation Tcl of programming language Tcl

A version of Tcl.

## Examples:

### Hello, World! - Tcl (215):

``````puts "Hello, World!"
``````

### Factorial - Tcl (273):

This example uses iterative factorial definition. In Tcl 8.4 values of factorials starting with 13! are calculated incorrectly due to overflow. In later versions and other implementations all values are correct.

``````set fact 1
for {set i 0} {\$i <= 16} {incr i} {
puts "\$i! = \$fact"
set fact [expr {\$fact * (\$i + 1)}]
}
``````

### Quadratic equation - Tcl (274):

``````set A [gets stdin]
if {\$A==0} {
return
}
set B [gets stdin]
set C [gets stdin]
set D [expr {\$B*\$B-4*\$A*\$C}]
set r [expr {-0.5*\$B/\$A}]
set i [expr {0.5*sqrt(abs(\$D))/\$A}]
if {\$D==0} {
puts "x = \$r"
} elseif {\$D>0} {
puts "x1 = [expr {\$r+\$i}]"
puts "x2 = [expr {\$r-\$i}]"
} else {
puts "x1 = (\$r, \$i)"
puts "x2 = (\$r, [expr {-\$i}])"
}
``````

### CamelCase - Tcl (315):

This example shows character-wise string processing. A regular expression is used to check whether current character is a letter.

``````set S [gets stdin]
set S [string tolower \$S]
set L [string length \$S]
set lastSpace 1
set cc ""
for {set i 0} {\$i < \$L} {incr i} {
set letter [string index \$S \$i]
if { [string match {[a-z]} \$letter] } {
if { \$lastSpace == 1 } { set letter [string toupper \$letter] }
append cc \$letter
set lastSpace 0
} else {
set lastSpace 1
}
}
puts \$cc
``````

### Fibonacci numbers - Tcl (386):

This example uses iterative definition of Fibonacci numbers.

``````set fib1 0
set fib2 1
set s ""
for {set i 0} {\$i < 16} {incr i} {
set fib3 [expr {\$fib1 + \$fib2}]
set fib1 \$fib2
set fib2 \$fib3
append s "\$fib1, "
}
puts "\$s..."
``````

### Fibonacci numbers - Tcl (387):

This example uses tail recursion to calculate the numbers. `eval` command allows to evaluate the result of calling `fib` with given arguments without declaring `fib` as part of any namespace.

``````proc fib {f1 f2 n} {
if {\$n==0} {
return \$f1
} else {
return [eval fib \$f2 [expr {\$f1 + \$f2}] [expr {\$n - 1}]]
}
}

set s ""
for {set i 0} {\$i < 16} {incr i} {
append s [eval fib 1 1 \$i] ", "
}
puts "\$s..."
``````