Check if a number is a whole number

Write a function that takes a number (a) as argument. If a is a whole number (has no decimal place), return true. Otherwise, return false.
function
myFunction
(
a
)
{

return
}
Test Cases:
myFunction(4)
Expected
true
myFunction(1.123)
Expected
false
myFunction(1048)
Expected
true
myFunction(10.48)
Expected
false