Is there a Swift equivalent to the 'Filter' function in Python?

Question

In python, it is incredibly simple to remove unwanted items from a string/list using the 'filter' function which can be used in conjunction with 'lambda' functions. in python, it's as simple as:

a = "hello 123 bye-bye !!£$%$%"
b = list(filter(lambda x: x.isalpha(), a))
c = "".join(b)
print(c) #Which would print "hellobyebye"

Is there any way to easily replicate this in swift without first converting to unicode and then checking if the unicode value is within a certain range? Also, are there any 'lambda' like things in swift?

Answer 1

Yes, there is an equivalant Filter function in Swift:

Filter

The filter method takes a function (includeElement) which, given an element in the array, returns a Bool indicating whether the element should be included in the resulting array. For example, removing all the odd numbers from the numbers array could be done like this:

 let numbers = [ 10000, 10303, 30913, 50000, 100000, 101039, 1000000 ] let evenNumbers = numbers.filter { $0 % 2 == 0 } // [ 10000, 50000, 100000, 1000000 ] 

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