Error when inserting one number in textbox-CodePudding

I have this code that takes input from a textbox and does this

if user inserts number 12 the program must print 0000000...(until 30 0)12 this is my code

String zero = "00000000000000000000000000000000";
getnumber = zero.substring(0, 32 - getnumber.length())   getnumber;

the code works fine until i insert only one number example 3 it will crash. Any idea why this happens?

CodePudding user response：

You must put -1 to the length.

String zero = "00000000000000000000000000000000";
getnumber = zero.substring(0, 32 - getnumber.length()-1)   getnumber;

This worked for me.

CodePudding user response：

Seems to me that you are trying to pad the number with zeroes. If that's the case, I highly suggest you check out this answer and use functions that are already a part of the language instead of reinventing them.