Starting flow control.
If statements.
Behavior as expected. Note the comparison operator uses double equals ==. A single = is an assignment operator.
Note that elsif is not spelled correctly. That took me a while to realize why the code didn't work right.
unless checks for false value, opposite of if
exclamation as a prefix is like "not" -- != means "not equal"
&& conjunction
|| disjunction
How to use if, else, and elsif
How to use comparators / relational operators like ==, !=, <, <=, >, and >=
How to use boolean / logical operators like &&, ||, and !
String control with a daffy duckifyer. gsub
Check substrings .include?
Starting loops
while, until, for
no increment operator like ++ or --
instead, uses += with an delta value
range in 1...10 (exclude the end value) or in 1..10 (include end value)
loop method -- the iterator
break to exit a loop
next to skip an iteration
arrays to store multiple values
another iterator .each
I was a public school teacher in New York City for over 16 years. Now I teach mathematics at an international school in Frankfurt am Main, Germany. Teaching was not my first career. I was a Master Teaching Fellow with Math for America, as well as a NY State Master Teacher. This blog is intended as a spot for me to record some of my observations.
Saturday, April 18, 2015
Learning Ruby part II
Basic tutorial at code.org was just that -- basic.
Now I'm trying their next tutorial, which seems to deal with input and string manipulation.
gets accepts user input
gets inserts a blank line after the input. the method .chomp removes the line
gets.chomp accepts user input without adding an extra line
Now I'm trying their next tutorial, which seems to deal with input and string manipulation.
gets accepts user input
gets inserts a blank line after the input. the method .chomp removes the line
gets.chomp accepts user input without adding an extra line
Monday, April 13, 2015
Learning Ruby part I
I have been given a task which requires I learn Ruby. I will try.
I've installed Ruby on my laptop (from links at ruby-lang.org). I found a tutorial on code academy. So I'll see where this leads.
notes:
data types: number, boolean, and string
assignment operator: equal sign
exponentiation: **
modulo: %
print: sends to screen
puts: adds blank line after screen output. hmmm?
I see. print leaves the next output right there, puts goes to the beginning of the next line.
strings have .length
and .reverse
and .upcase and .downcase
hashmark for single line comments
=begin to =end for multi-line comments
I've installed Ruby on my laptop (from links at ruby-lang.org). I found a tutorial on code academy. So I'll see where this leads.
notes:
data types: number, boolean, and string
assignment operator: equal sign
exponentiation: **
modulo: %
print: sends to screen
puts: adds blank line after screen output. hmmm?
I see. print leaves the next output right there, puts goes to the beginning of the next line.
strings have .length
and .reverse
and .upcase and .downcase
hashmark for single line comments
=begin to =end for multi-line comments
Subscribe to:
Posts (Atom)