红宝石 |字符串字节片方法

byteslice是 Ruby 中的 String 类方法，用于字节引用。

Syntax: str.byteslice

Parameters: Here, str is the specified string.

Returns:

• A substring of one byte at that position if only a single integer passed.
• A substring starting at the offset given by the first, and a length is given by the second if the two integers passed.
• A substring containing bytes at offsets given by the range if the range is passed.
• nil if the length is negative or initial offset falls outside the string or the beginning of the range is greater than the end.

注意：如果偏移量为负数，则从字符串的末尾开始计算。

示例 1：

# Ruby program to demonstrate
# the byteslice method
     
# Taking a string and
# using the method
puts "Ruby String".byteslice(9)
puts "Methods".byteslice(2, 4)

输出：

n
thod

示例 2：

# Ruby program to demonstrate
# the byteslice method
     
# Taking a string and
# using the method
puts "Ruby String".byteslice(-1)
puts "Methods".byteslice(1..4)

输出：

g
etho