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





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 interpreter; however, variable substitution and command substi-
       tution 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                                

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)


KEYWORDS
       element, index, list



Tcl                                   8.4                            lindex(n)