Swift将整数转换为2个字符的十六进制字符串

Question

I am trying to get a two character hex value from an integer: 我想从一个整数中获取一个两个字符的十六进制值：

let hex = String(format:"%2X", 0)
print ("hex = \(hex)")

hex = "0" 十六进制=“0”

How can I format String to result in always 2 characters, in this case I would want 如何格式化String以产生总共2个字符，在这种情况下我想要

hex = "00" 十六进制=“00”

Answer 1

You can add a padding 0 before the formatter string: 您可以在格式化程序字符串之前添加填充0：

let hex = String(format:"%02X", 0)

Result: 结果：

let hex = String(format:"%02X", 0) // 00
let hex = String(format:"%02X", 15) // 0F
let hex = String(format:"%02X", 16) // 10