Add zero-padding to a string

问题

How do I add \"0\" padding to a string so that my string length is always 4?

Example

If input \"1\", 3 padding is added = 0001
If input \"25\", 2 padding is added = 0025
If input \"301\", 1 padding is added = 0301
If input \"4501\", 0 padding is added = 4501

回答1:

You can use PadLeft

var newString = Your_String.PadLeft(4, '0');

回答2:

myInt.ToString("D4");

回答3:

string strvalue="11".PadRight(4, '0');

output= 1100

string strvalue="301".PadRight(4, '0');

output= 3010

string strvalue="11".PadLeft(4, '0');

output= 0011

string strvalue="301".PadLeft(4, '0');

output= 0301

回答4:

"1".PadLeft(4, '0');

回答5:

int num = 1;
num.ToString("0000");

来源：https://stackoverflow.com/questions/3122677/add-zero-padding-to-a-string