Logical xor operator

True when exactly one of two values is truthy.

JavaScript Version 1.0.0 · MIT · .md

function xor([a, b]) { return Boolean(a) !== Boolean(b); }

Input & expected output

[
  true,
  false
]

true

The edge case

[
  "",
  "y"
]

true

Know the limits

• Operands are converted to booleans first. The original’s (a && !b) || (!a && b) returns an operand instead: for the edge case it returns "y", not true.
• The lab takes the two values as an array.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Identity function — Return the argument unchanged.
• Box handler — Chain transformations on a value, then unwrap the result.
• Check if a value is a function — True for anything callable: functions, arrows, async and generator functions, classes.