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lindex(n)                                   Tcl Built-In Commands                                  lindex(n)



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NAME
       lindex - Retrieve an element from a list

SYNOPSIS
       lindex list ?index...?
____________________________________________________________________________________________________________

DESCRIPTION
       The  lindex command accepts a parameter, list, which it treats as a Tcl list. It also accepts zero or
       more indices into the list.  The indices may be presented either consecutively on the  command  line,
       or grouped in a Tcl list and presented as a single argument.

       If no indices are presented, the command takes the form:
              lindex list
       or
              lindex list {}
       In this case, the return value of lindex is simply the value of the list parameter.

       When  presented  with  a  single  index, the lindex command treats list as a Tcl list and returns the
       index'th element from it (0 refers to the first element of the list).   In  extracting  the  element,
       lindex observes the same rules concerning braces and quotes and backslashes as the Tcl command inter-preter; interpreter;
       preter; however, variable substitution and command substitution do not occur.  If index  is  negative
       or  greater  than or equal to the number of elements in value, then an empty string is returned.  The |
       interpretation of each simple index value is the same as for the  command  string  index,  supporting |
       simple index arithmetic and indices relative to the end of the list.

       If  additional  index arguments are supplied, then each argument is used in turn to select an element
       from the previous indexing operation, allowing the script to select elements from sublists.  The com-mand, command,
       mand,
              lindex $a 1 2 3
       or
              lindex $a {1 2 3}
       is synonymous with
              lindex [lindex [lindex $a 1] 2] 3

EXAMPLES
              lindex {a b c}
                    -> a b c
              lindex {a b c} {}
                    -> a b c
              lindex {a b c} 0
                    -> a
              lindex {a b c} 2
                    -> c
              lindex {a b c} end
                    -> c
              lindex {a b c} end-1
                    -> b
              lindex {{a b c} {d e f} {g h i}} 2 1
                    -> h
              lindex {{a b c} {d e f} {g h i}} {2 1}
                    -> h
              lindex {{{a b} {c d}} {{e f} {g h}}} 1 1 0
                    -> g
              lindex {{{a b} {c d}} {{e f} {g h}}} {1 1 0}
                    -> g

SEE ALSO
       list(n),  lappend(n),  linsert(n), llength(n), lsearch(n), lset(n), lsort(n), lrange(n), lreplace(n), |
       string(n)


KEYWORDS
       element, index, list



Tcl                                                  8.4                                           lindex(n)