Alex Jiang

August 30, 2014

List and Array

List

• init. one element in list. $fred[0] = "do";
• maximum element index: $index = $#fred
• last value of list: $last = $fred[$#fred] or $last = $fred[-1]
• out-of-bound subscripts return undef, print nothing
• assigning beyond $#list, just stretches the list, filling the middle element with undefined. e.g. $fred[20] = hello, then $fred[1…19] is there, but undefined

August 30, 2014

Perl w1

• a little thought on Perl
  • make sure you know the context when writing perl program
  • make sure you understand which type of var you are using
    • scalar always start with $
    • list always start with @
    • dict always start with %

July 1, 2014

Never in all their history have men been able truly to conceive of the world as one: a single sphere, a globe, having the qualities of a globe, a round earth in which all the directions eventually meet, in which there is no center because every point, or none, is center — an equal earth which all men occupy as equals. The airman's earth, if free men make it, will be truly round: a globe in practice, not in theory.