Code A: var x = 10; y = --x + 1;

alert(y);

Code B: var x = 10;

y = x-- + 1;

alert(y);

What is the output for code A and B?

a)10,11

b)10,10

c)11,10

d)11,11

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JavaScript programs may generate unexpected results if a programmer accidentally uses an assignment operator (`=`

), instead of a comparison operator (`==`

) in an if statement.

This `if`

statement returns `false`

(as expected) because x is not equal to 10:

Addition is about adding numbers.

Concatenation is about adding strings.

In JavaScript both operations use the same `+`

operator.

Because of this, adding a number as a number will produce a different result from adding a number as a string: