console.log(1 + 2);
console.log(1 + "s");

// Number + Number -> addition
1 + 2 // 3

// Boolean + Number -> addition
true + 1 // 2

// Boolean + Boolean -> addition
false + false // 0

// Number + String -> concatenation
5 + 'foo' // "5foo"

// String + Boolean -> concatenation
'foo' + false // "foofalse"

// String + String -> concatenation
'foo' + 'bar' // "foobar"

operand + operand = result

var result =  'b' + 'a' + + 'a' + 'a';

>> baNaNa

var result = [1, 2, 3] + [4, 5, 6];
console.log(result);

>> '1,2,34,5,6'