Positive infinity.
A positive number greater than MAX_VALUE has the value POSITIVE_INFINITY.
POSITIVE_INFINITY has the string representation ? (question mark) or +? (plus sign, question mark).
Division by zero results in infinity.
function p(stuff) { print("<<<" + stuff + ">>>"); } try { p(Number.POSITIVE_INFINITY.toString()); // prints <<<?>>> p(Number.POSITIVE_INFINITY.valueOf()); // prints <<<Infinity>>> var n = new Number(1.7976931348623157E309); if (n == Number.POSITIVE_INFINITY) { p(n + " = Number.POSITIVE_INFINITY"); // prints <<<Infinity = Number.POSITIVE_INFINITY>>> } if ((5/0) == Number.POSITIVE_INFINITY) { p("division by 0 = Number.POSITIVE_INFINITY"); //prints <<<division by 0 = Number.POSITIVE_INFINITY>>> } } catch(e) { p("Error = " + e); }