lindex(n) - phpMan

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  consecu-
       tively 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 interpreter; 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 arith- |
       metic 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 command,
              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)

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