Version 2 of Tcl Tutorial Lesson 17

String Subcommands - length index range

Tcl commands often have "subcommands". The string command is an example of one of these. The string command treats its first argument as a subcommand. Utilizing subcommands is a good way to make one command do multiple things without using cryptic names. For instance, Tcl has string length instead of, say, slength.

This lesson covers these string subcommands:

string length str

Returns the length of str.

string index str i

Returns the ith character from str.

string range str first last

Returns a string composed of the characters from first to last taken from str.

Example

set string "this is my test string"

puts "There are [string length $string] characters in \"$string\""

puts "[string index $string 1] is the second character in \"$string\""

puts "\"[string range $string 5 10]\" are characters between the 5'th and 10'th"

There are 22 characters in "this is my test string"
h is the second character in "this is my test string"
"is my " are characters between the 5'th and 10'th