Truncate number to two decimal places without rounding

Question

Suppose I have a value of 15.7784514, I want to display it 15.77 with no rounding.

var num = parseFloat(15.7784514);
document.write(num.toFixed(1)+\"


        

Answer 1

Another single-line solution :

number = Math.trunc(number*100)/100

I used 100 because you want to truncate to the second digit, but a more flexible solution would be :

number = Math.trunc(number*Math.pow(10, digits))/Math.pow(10, digits)

where digits is the amount of decimal digits to keep.

See Math.trunc specs for details and browser compatibility.