Ruby Array Select First N Elements

Hammerhead find executes the block you provide for each element in the array.

Ruby array select first n elements. When a size and an optional default are sent an array is created with size copies of default take notice that all elements will reference the same object default. If the last expression in the block evaluates to true the find method returns the value and stops iterating. See also array last for the opposite effect. Returns a new array.

You can learn about boolean values in ruby by reading this article. So to retrieve the first element from our emails array we append the element s index to the variable using square brackets like this. The take n method returns the first n elements of the array. Returns the first element or the first n elements of the array.

In the first form if no arguments are sent the new array will be empty. A negative index is assumed relative to the end of the array that is an index of 1 indicates the last element of the array 2 is the next to last element in the array and so on. If the array is empty the first form returns nil and the second form returns an empty array. Array indexing starts at 0 as in c or java.

To access a specific item or element of an array you reference its index or its position in the array. The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter. If it doesn t find anything after iterating through all of the elements it returns nil. 1 2 3 4 5 6 select n n even.

Ruby arrays can hold objects such as string integer fixnum hash symbol even other array objects. This will do the same thing as the first example in the introduction but with a lot less code. Inside the block you have to return something that evaluates to true or false and select will use that to filter your array. Ruby array select collect map methods.