JavaScript Subtraction

LeftOperand - RightOperand

10 - 3;         // 7
10 - "4";       // 6   (String "4" coerced to Number 4)
10 - true;      // 9   (Boolean true coerced to Number 1)
10 - false;     // 10  (Boolean false coerced to Number 0)
10 - null;      // 10  (null coerced to Number 0)
10 - undefined; // NaN (undefined coerced to NaN)

-Operand

-5;             // -5
-"42";          // -42 (String coerced to Number, then negated)
-true;          // -1  (Boolean coerced to Number, then negated)
-"text";        // NaN (Unparseable string coerces to NaN)

10 - { valueOf: () => 3 }; // 7
10 - {};                   // NaN ({} coerces to "[object Object]", then to NaN)
10 - [];                   // 10  ([] coerces to "", then to 0)
10 - [2];                  // 8   ([2] coerces to "2", then to 2)
10 - new Date(0);          // 10  (Date coerces to its epoch timestamp, 0)

20n - 5n;       // 15n
-42n;           // -42n
20n - 5;        // TypeError: Cannot mix BigInt and other types

Infinity - 5;               // Infinity
Infinity - Infinity;        // NaN
-Infinity - Infinity;       // -Infinity
0 - 0;                      // 0
-0;                         // -0 (Unary negation of 0 yields negative zero)