Subtraction (-)

The - operator is overloaded for two types of operands: number and BigInt. It first coerces both operands to numeric values and tests the types of them. It performs BigInt subtraction if both operands become BigInts; otherwise, it performs number subtraction. A TypeError is thrown if one operand becomes a BigInt but the other becomes a number.

5 - 3; // 2
3 - 5; // -2

Other non-BigInt values are coerced to numbers:

"foo" - 3; // NaN; "foo" is converted to the number NaN
5 - "3"; // 2; "3" is converted to the number 3

2n - 1n; // 1n

You cannot mix BigInt and number operands in subtraction.

2n - 1; // TypeError: Cannot mix BigInt and other types, use explicit conversions
2 - 1n; // TypeError: Cannot mix BigInt and other types, use explicit conversions

To do subtraction with a BigInt and a non-BigInt, convert either operand:

2n - BigInt(1); // 1n
Number(2n) - 1; // 1

• Addition (+)
• Division (/)
• Multiplication (*)
• Remainder (%)
• Exponentiation (**)
• Increment (++)
• Decrement (--)
• Unary negation (-)
• Unary plus (+)