indexOf
Let's talk about some
array methods like indexOf().
This method searches for
a given element in an array.
It returns the first index
at which the element is found.
In the example given above,
"banana" is present at index 1 and 3.
The indexOf method returns the value 1,
as that is the first index
at which "banana" can be found.
If the element is not found
in the array,
it returns -1.
In the example given above,
"orange" is not present in the array.
Therefore,
the returned value is -1.
We can also specify the index
from which the indexOf()
method should start
looking for the element.
In the example given above,
the search starts
from the index 2.
Therefore,
the returned value is 3.
lastIndexOf
The lastIndexOf() method is
similar to the indexOf() method.
However,
it looks for the given element
from the last index to the first.
The lastIndexOf() method
returns the last index
at which the element is found.
If the element is not found,
it returns -1.
In the example given above,
"banana" is present at index 1 and 3.
The lastIndexOf method returned value 3,
since it is the last index at which
the element "banana" is found.
We can also specify the index
from which the lastIndexOf()
method should start
looking for the element.
In the example given above,
the search starts
from the index 2.
Therefore,
the returned value is 1.