What is the result of the statement sum(1, '2')?

The statement sum(1, '2') invokes the addition operation with two arguments: a number (1) and a string ('2'). In JavaScript, when an operation involves both a number and a string, the number is implicitly converted to a string to perform the concatenation. This is due to JavaScript's type coercion behavior.

In this case, the number 1 is converted to the string "1", and when it is concatenated with the string "2", the result is "12". Therefore, the output of sum(1, '2') is "12" as the result of the concatenation of the two strings.

This behavior can sometimes lead to unexpected results for those who may expect mathematical addition to occur, given that one of the operands is a number. Understanding how JavaScript handles type conversion in such scenarios is crucial for correctly anticipating the outcome of mixed-type operations.