Alex Jiang

August 30, 2014

Dynamic Binding in Objective-C

What is Dynamic Binding

Determining the methods of different kinds of objects to invoke at runtime rather than at compile-time.

August 30, 2014

RegEx cont.

Variables

• Match vars.
  • if regex have parens i.e. groups
  • if group got successful match
    • then the content of matched pattern stored in $1, meaning first match against first group
    • e.g. /(\S+)(\S+),(\S+)/ corresponding matched content is print $1 $2 $3
  • classical match idiom: if(xx =~ xx) do sth else die
  • three special vars.
    • a regex matching a string divides the string into 3 pars
    • $&: the part actually matched
    • $\backslash: the part before matched
    • $': the part after matched

August 30, 2014

SLP week1: A review

Design Choice

• Perl, is eager to give you the answer, and try its best to guess an answer for you!
• No reserved word, prefix with var distinguish data from build-ins (so developers can add more build-ins later on without conflicts)