创建macos命令行工具项目。

import Foundation

print("Type two input: ")

if let input1 = readLine(), let input2 = readLine(), let value1 = Int(input1), let value2 = Int(input2) {
    print("Sum=\(value1+value2)")
}

第一步

第二步

import Foundation

print("enter number one: ")
var sum = 0
if let num1 = Int(readLine()!) {
  sum += num1
}
print("enter number two: ")
if let num2 = Int(readLine()!) {
  sum += num2
}

print(sum)

首先创建一个sum变量，然后对于每个操作数，获取一个输入并将其转换为一个整数，您可以通过加法赋值运算符将其添加到sum中。

import Foundation

guard let a = Int(readLine()!), let b = Int(readLine()!) else {
    fatalError("expected a number got something else.")
}
print("mul = \(a * b)")
print("sum = \(a + b)")