Swift How to get integer from string and convert it into integer

I need to extract numbers from string and put them into a new array in Swift.

var str = "I have to buy 3 apples, 7 bananas, 10eggs"

I tried to loop each characters and I have no idea to compare between Characters and Int.

First, we split the string so we can process the single items. Then we use NSCharacterSet to select the numbers only.

import Foundation

let str = "I have to buy 3 apples, 7 bananas, 10eggs"
let strArr = str.split(separator: " ")

for item in strArr {
    let part = item.components(separatedBy: CharacterSet.decimalDigits.inverted).joined()

    if let intVal = Int(part) {
        print("this is a number -> \(intVal)")
    }
}

Swift 4:

let string = "I have to buy 3 apples, 7 bananas, 10eggs"
let stringArray = string.components(separatedBy: CharacterSet.decimalDigits.inverted)
for item in stringArray {
    if let number = Int(item) {
        print("number: \(number)")
    }
}