Pros

Simplicity

Probably the best part of CoffeeScript is its simplicity. CoffeeScript allows for a more concise and simplistic syntax than plain JavaScript. One simple but surprisingly time-saving feature is that CoffeeScript has no need for ; or {}, eliminating the need to spend hours finding out the place from which a } is missing.

Loops

Creating a loop that outputs the value of each item in an array unless the value is “monkey” in CoffeeScript is very easy.

animals = ["dog", "cat", "monkey", "squirrel"]
for item in animals when item isnt "monkey"
    console.log item

in CoffeeScript compiles to

var animals, i, item, len;

animals = ["dog", "cat", "monkey", "squirrel"];

for (i = 0, len = animals.length; i < len; i++) {
    item = animals[i];
    if (item !== "monkey") {
        console.log(item);
    }
}

in JavaScript, but they both output

dog
cat
squirrel

String Interpolation

CoffeeScript:

"Hello, #{user}, how are you today?"

JavaScript:

"Hello, " + user + ", how are you today?";