Javascript does not have functionality like Enumerable in ruby, it's even lacking an each method. All iteration has to be done with something while or more commonly for. The for statement has three parts:
- The initial condition
- The condition in which the loop should continue to run
- And the method to work towards an ending condition
Each of these are typically on a single line, seperated by a semicolon. Here is a simple example
var i;
for (i = 0; i < 10; i++) {
// repeatedly run code here, ten times (0-9)
}In this case our initial condition is i = 0, then the condition which this loop should continually run is while i < 10, finally the mysterious line i++ is equivalent to ruby i += 1, it increments the value by one, this is going to happen after each iteration over the code.
Although this idea does not specifically utelize an array, we can easily adapt it.
var people = ["Sally", "Bob", "Jim", "Jenny", "Becky", "Jessica"]
for (i = 0; i < people.length; i++) {
console.log(people[i]);
};While less common a while loop works just as well, it's also nearly the same syntax as Ruby.
i = 0;
while (i < 100) {
console.log(i);
i++;
}.forEach in Javascript is closer to the ruby .each method, although it's relatively new to javascript, older browsers will not support it (i.e. IE 8 :( ), so be careful to not use it if you are supporting those browsers.
[1,2,3,4].forEach(function(element, index, array) {
console.log(element);
})Similar to the .forEach, there is also a .map method in Javascript, which is identical to Rubys. But again, this is not available to older browsers.
[1,2,3,4].map(function(element, index, array) {
return element * 2;
})