Swift Identifiers

Swift Identifiers

Identifiers name variables, constants, types, functions, etc.

Rules for Identifiers

Identifiers must:

• Start with a letter or underscore.
• May include numbers after the first character.
• Avoid keywords unless escaped with backticks.

They can contain Unicode and must not start with a number.

let name = "Swift"
let π = 3.14
let _hidden = true

Escaping Keywords and Unicode

Escape keywords with backticks when needed, and remember identifiers can include Unicode characters.

let `switch` = "ok"   // escape a keyword using backticks
let 🐶 = "dog"          // Unicode identifier
print(`switch`, 🐶)

Use backticks to escape reserved words in identifiers, and remember Swift identifiers can include Unicode characters.