To process multi-byte characters correctly, you need to understand the difference between characters, columns, and bytes:

  • Characters are symbols in a code page, each of which is assigned a numeric value
  • Bytes are units of storage, each consisting of eight bits
  • Columns are units of width, indicating how much width a symbol requires on the monitor or on a printed report

To clarify, examine the following table, which shows two characters, one single-byte and one double-byte, and the byte and column count of each.

Table 1. Byte count and column count
Character Number of bytes Number of columns
A 1 1
2 2