When the block is omitted all.
Ruby array find all indexes.
Array indexing starts at 0 as in c or java.
Find index is a array class method which returns the index of the first array.
To access a specific item or element of an array you reference its index or its position in the array.
Index match if you do some gymnastics you can have it on one line without.
It is actually not that difficult to do so.
Using block version in ruby 1 8 7.
Here is a quick example.
Owner myself match index list.
Without a block on an array is effectively a test to see if all the items in the collection evaluate to true or conversely if there are any false or nil values in the array.
The index of the first element is zero.
If it doesn t find anything after iterating through all of the elements it returns nil.
Hammerhead find executes the block you provide for each element in the array.
If a block is given instead of an argument returns the index of the first object for which the block returns true.
Find l l.
The block usage was added in 1 8 7 so to get the same functionality in an earlier version of ruby you need to utilize the find method.
Ruby arrays can hold objects such as string integer fixnum hash symbol even other array objects.
Arrays are zero based.
Block condition to follow return.
Testing arrays for nils with enumerable all.
By running the following you can achieve that.
In the first form if no arguments are sent the new array will be empty.
Arrays can hold objects of any data type.
Uses this implied block.
If the last expression in the block evaluates to true the find method returns the value and stops iterating.
In ruby indexes start at zero.
The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter.
Index value of the array elements.
So to retrieve the first element from our emails array we append the element s index to the variable using square brackets like this.
A variable can hold only one item at a time.
These items are called elements of the array.
Each element can be referred to by an index.
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.
Returns a new array.
Since everything in ruby evaluates to true except for false and nil using all.
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.
I often need to get the indices of all the elements that match a given condition.
