问题
I have to fix malformed zipcodes. The people who exported the data treated the zipcode as a numeric and as a result New Jersey and Puerto Rico zipcodes, which begin with a leading zero and two leading zeroes respectively, have been truncated.
They're supposed to be all five characters (no zip+4 data is involved). I know how to zero-pad brute-force by getting the length and prepending the appropriate number of zeroes to the string, but is there a more elegant way that draws on the "native" features of C#? For example, can a mask be applied that would turn "9163" into "09163" and "904" into "00904" without my having to get the length of the value?
回答1:
If you have an integer value, use the composite format string to ensure padding:
var padded1 = 1.ToString("D5");
The number after D is for the length you need the value to be in.
回答2:
string test = "9163";
test = test.PadLeft (5, '0');
回答3:
string s = string.Format("{0:00000}", 1234);
Console.WriteLine(s);
Format String Reference
回答4:
string one = a.ToString("00000"); // 00904
来源：https://stackoverflow.com/questions/16838782/simple-and-elegant-way-to-zero-pad-a-value-in-c-sharp