Word count. Sometimes a document may have a certain file size, but the word count is clearer for estimating its length. A function that counts words in Swift can be developed.
With a for-loop over the characters, we can test each character with Character type properties. Some logic is required to test for whitespace.
Step 2 We test the previous character to see if it is whitespace that could start a word. We also test the current character for a letter.
Step 3 Because we have to test two characters at once on each iteration, we need to set the previous character here.
Step 4 We return the total number of words in the string, based on the result of the iterative function.
func countWords(source: String) -> Int {
var count = 0
var previous: Character = " "// Step 1: loop over string characters.
for c in source {
// Step 2: test previous character for whitespace, and current for letter, number or punctuation.
if previous.isWhitespace {
if c.isLetter || c.isNumber || c.isPunctuation {
count += 1
}
}
// Step 3: set previous.
previous = c
}
// Step 4: return count of words.
return count
}
// Use word counting function.
let input = "Cat, bird and dog."
let result = countWords(source: input)
print(result)4
Summary. It is possible to develop an iterative word count algorithm in Swift, and this gives accurate results for English. It is also fast, as no regular expressions are used.
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