trusty (3) lindex.3tcl.gz

Provided by: tcl8.4-doc_8.4.20-7_all bug

NAME

       lindex - Retrieve an element from a list

SYNOPSIS

       lindex list ?index...?
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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 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.  If index has the value end,
       it refers to the last element in the list, and end-integer refers to the last element in the  list  minus
       the specified integer offset.

       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                                                                  │

EXAMPLESlindex {a b c}  => a b clindex {a b c} {} => a b clindex {a b c} 0 => alindex {a b c} 2 => clindex {a b c} end => clindex {a b c} end-1 => blindex {{a b c} {d e f} {g h i}} 2 1 => hlindex {{a b c} {d e f} {g h i}} {2 1} => hlindex {{{a b} {c d}} {{e f} {g h}}} 1 1 0 => glindex {{{a b} {c d}} {{e f} {g h}}} {1 1 0} => g

SEE ALSO

       list(3tcl),  lappend(3tcl),  linsert(3tcl),  llength(3tcl),   lsearch(3tcl),   lset(3tcl),   lsort(3tcl), │
       lrange(3tcl), lreplace(3tcl)

KEYWORDS

       element, index, list