A string concatenation task in JavaScript: what will be displayed on the screen and why? (example with + operator and strings/numbers)

In JavaScript, the + operator is used for both addition of numbers and concatenation of strings. If at least one of the operands is a string, the others are converted to strings, and concatenation occurs.

Example:

console.log(1 + 2 + '3'); // '33'
console.log('1' + 2 + 3); // '123'

Explanation:

• In the first case, 1 + 2 are added as numbers, resulting in 3, then 3 + '3' — the number 3 is converted to a string and concatenated, resulting in '33'.
• In the second case, '1' + 2 — string + number, the number is converted to a string, resulting in '12', then '12' + 3 — again concatenation, resulting in '123'.

Thus, the order of operations and operand types affect the result.