Calculating on the Fly

JavaScript can do everything your scientific calculator can.

1. Basic Operations

• +, -, *, /.
• % (Remainder): 5 % 2 = 1. Useful for checking parity (even/odd).
• ** (Exponentiation): 2 ** 3 = 8.

2. String Addition (Concatenation)

The + operator is special. If at least one operand is a string, the result will be a string.

alert(2 + 2 + '1'); // "41" (first 2+2=4, then 4 + '1' = "41")
alert('1' + 2 + 2); // "122" (immediately turned into strings)

Important: Other operators (-, *, /) always turn everything into numbers!

3. Shorthand Assignment

let n = 2;
n += 5; // n = n + 5 (now 7)
n *= 2; // n = n * 2 (now 14)

4. Increment / Decrement

• counter++ — increase by 1.
• counter-- — decrease by 1.