let x = 1, y = 2, z = 3, A = true
1. print(x, y, z, A) 默认输出有空格隔开 `separator ` 且具有换行功能
输出:1 2 3 true
2. print(x, y, z, separator:"*") 手动设置以 `*` 结尾
输出:1*2*3
3. `terminator `结尾标识符,加上之后不具有换行功能
print(x, y, z, separator:"--", terminator:"结尾")
print(">>>>>>")
输出:1--2--3结尾>>>>>>
4. 变长的参数
print("hello", 1, 2, 3, 4, 5, 6, 7, 8, 9, separator:" ", terminator:".")