POSITIVE_INFINITY The POSITIVE_INFINITY property is returned when a calculation returns a number greater than the largest Positive number available to JavaScript, which is 1.7976931348623157e+308. syntax: Number.POSITIVE_INFINITY EXAMPLE if (Math.Sqrt(-4) != Number.POSITIVE_INFINITY) { document.write("The number is equal to POSITIVE_INFINITY!!"); } else { document.write("The number is NOT equal to POSITIVE_INFINITY!!"); } The example takes the square root of -4 and compares it to the Number.POSITIVE_INFINITY. It then writes the appropriate document.write statement to the screen.