Functions are defined using the function keyword.
function eat (food) {
console.log("Eating some " + food);
}
eat("pizza"); // <-- Argument plugs into variable in JS the same way as in Ruby.
When a function is created, the function name can also be used as a variable.
console.log(eat);
Instead of using do...end, braces are the opening and closing syntax. Instructions must end with a semicolon (virtually every line).
Parantheses required around condition of if/else statements. AND empty arguments.
process(sample_array);
noParameter();
When first assigned, variables must be declared with 'var'. Otherwise, you will define a global variable, which will screw you all up if you use generic naming conventions.
var positions = [];
- Where a variable is usable is entirely dependent on where it was defined.
function nationality (nation, array) {
var counter = 0;
array.forEach(function (totalStudents) {
if (totalStudents === nation) {
counter += 1;
}
});
return counter;
}
module.exports = nationality;
The counter variable is only accessible from inside the nationality function.
console.log(counter);
Will return an error.
- JS equivalent of Ruby's .each is .forEach.
pets ["dogs", "cats", "birds"]
var pets = ["dogs", "cats", "birds"];
pets.forEach(function (pets) {
console.log(pets);
});
- JS equivalent of Ruby's .select is .filter.
pets ["dogs", "cats", "birds"]
var pets = ["dogs", "cats", "birds"];
- JS has a .map loop like Ruby.
pets ["dogs", "cats", "birds"]
var pets = ["dogs", "cats", "birds"];
- JS also has a .reduce loop like Ruby.
pets ["dogs", "cats", "birds"]
var pets = ["dogs", "cats", "birds"];
-
JavaScript uses 3 equal signs in place of Ruby's two for equations. === ≠ ==
- The type for NaN is Number. ...??!