How to make changes in a Git repo
git status
Lists all new or modified files to be committed
git add [file]
Snapshots the file in preparation for versioning
git reset [file]
Unstages the file, but preserve its contents
git diff
Shows file differences not yet staged
git diff --staged
Shows file differences between staging and the last file version
git commit -m "[descriptive message]"
Records file snapshots permanently in version history
# Comment text
Comments the text, Ruby will ignore everything that is marked with #.
variable = some_value
Declare a variable.
puts text
Prints the argument to the console with new line.
object.method(arguments)
Calling a method on object that accecpts an argument. It may also not require an argument.
def name(parameter)
method body
end
This defines a new method that accepts a parameter.
CONSTANT = some_value
Like a variable but has a known value that should never change and always refer to the same value.
"A string and and an #{expression}"
Combines a string with a variable or Ruby expression.
string[position]
Access the character the given position. Index is set at 0.
array[position]
Access the position in an array, Indexed at 0.
array << element
This pushes element into the bottom of the array.
array.each do |e| .. end
Iterates over the array. Each element is the assigned the element 'e'.
{key => value}
Key value pair in hashes. Easy memory trick. Think of a grocery list, the fish is the key and salmon is the hash (or value assigned).
// Comment text
Comments the text, JavaScript will ignore everything that is marked with //.
console.log(text)
Prints 'text' to the console.
for ([initialization]; [condition]; [final-expression])
The for loop syntax. Useful for iteration.
for (variable in object) { .. }
For..in statement iterates over the enumerable properties of an object.
var i = x
Declare a variable with the 'var' and set it equal x.
function greet(name) { .. }
Create a function. Functions are built for a singular piece of recurring logic. Accepts argument.
var obj ={}
JavaScript objects, similiar to Ruby Hashes..see above
if (condition == condition) { ..} else { .. };
If/else statement syntax. If conditions are met the code executes else moves on to next argument.
condition ? example1 : example2
Ternary operator. Operates the same as an if/else statement with boolean operator.
Math.random();
Generates a random number from 0 to 1. Math.floor will round integer down. Math.ceil will round up.
