Why is there no logical xor in JavaScript?

Question

Why is there no logical xor in JavaScript?

Answer 1

Here's an alternate solution that works with 2+ variables and provides count as bonus.

Here's a more general solution to simulate logical XOR for any truthy/falsey values, just as if you'd have the operator in standard IF statements:

const v1 = true;
const v2 = -1; // truthy (warning, as always)
const v3 = ""; // falsy
const v4 = 783; // truthy
const v5 = false;

if( ( !!v1 + !!v2 + !!v3 + !!v4 + !!v5 ) === 1 )
  document.write( `[ ${v1} XOR ${v2} XOR "${v3}" XOR ${v4} XOR ${v5} ] is TRUE!` );
else
  document.write( `[ ${v1} XOR ${v2} XOR "${v3}" XOR ${v4} XOR ${v5} ] is FALSE!` );

The reason I like this, is because it also answers "How many of these variables are truthy?", so I usually pre-store that result.

And for those who want strict boolean-TRUE xor check behaviour, just do:

if( ( ( v1===true ) + ( v2===true ) + ( v3===true ) + ( v4===true ) + ( v5===true ) ) === 1 )
  // etc.

If you don't care about the count, or if you care about optimal performance: then just use the bitwise xor on values coerced to boolean, for the truthy/falsy solution:

if( !!v1 ^ !!v2 ^ !!v3 ^ !!v4 ^ !!v5 )
  // etc.