ZipFormatUS

The layouts a US ZIP code can take: five digits, hyphenated ZIP+4, or bare nine digits.

A US ZIP code has two lengths. The short form is five digits: "90210". The long form, called ZIP+4, adds four more digits that pin the address down to a block or a building — and those nine digits sometimes arrive hyphenated ("90210-1234") and sometimes as one unbroken run ("902101234"). ZipFormatUS names these layouts so you can tell the reader which one your data must match — or say Any and take whatever arrives.

Members

Member	Meaning
Any	No constraint: every supported layout passes. A five-digit code comes back as five digits, a ZIP+4 comes back hyphenated. This is the default.
Five	The five-digit form, e.g. "90210".
Plus4	The hyphenated ZIP+4 form, e.g. "90210-1234".
Plus4Digits	The unseparated nine-digit ZIP+4, e.g. "902101234". Accepted on input only — the returned value is always hyphenated.

Where it is used

One method takes it: Zip on CkUS, through its format parameter. The format constrains — it never converts. A five-digit code cannot gain a +4 segment, and dropping one would lose data; a value in the wrong layout is simply rejected. The one rewrite is the hyphen: the bare nine-digit form is returned hyphenated, so every code has a single canonical spelling.

Quick look

using SafeCoder.CommonKit;
using SafeCoder.CommonKit.Enums;

CkUS.Zip("90210-1234");               // -> "90210-1234"  (Any is the default: every layout passes)

CkUS.Zip(
    input: "90210-1234",
    format: ZipFormatUS.Five
);                                    // -> ""  (not five digits: rejected, empty out)

CkUS.Zip(
    input: "902101234",
    format: ZipFormatUS.Plus4Digits
);                                    // -> "90210-1234"  (nine bare digits in, hyphenated out)