General
- method_name() to run a method with no parameters
- .split splits a string into an array based on spaces
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- .split() splits a string into an array with the value inside the parens
- "\n" is class block
- Make sure the remember that an array starts with 0, and so the top number needs to be subtracted by 1
- .gsub(/thing/, "substitute") substitutes "thing" with "substitute"
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- if "thing" is a parenthesis, use "" instead of //
- {} is used for a code block (as opposed to do and end), but also for hash. It might be worth using do and end for a code block
- refactor means cleaning up code
Arrays
- << element to add things to an array (modify array)
- .push(element) to add things (modify array)
- .pop removes the last element (modify array)
- .unshift(element) to add element to the beginning
- .shift returns the first element that has been popped off
- .map {} performs things in an array but shows the output in the array, where as each {} shows the output in individual array elements
- .each_with_index {} shows each of the element with the position (e.g.0, 1, 2, 3)
- .index(element) to find the position of the element in the array. If there are multiple elements of the same values, it will show the position of the first one.
- .select {} eliminates something in an array
- array[x..y] is a range and will display the elements between x and y positions
Range
- x..y range from x to y
- x…y range from x to y-1
Hash
- Hash literal is name = {}
- Hash is how the internet organizes information: key value pairs
name = { key: value, key2: value2. }
older way:
name = { :key => value, :key2 => value2, }
Symbol
- A symbol has a value that equals its name
- Format of :name
Loop
for i in 1..100 puts i end
Block
- Block is like a function with pipes. Pipes perform the same function as a paren in a method
a.each do |x| puts x end
Boolean operator has a question mark at the end