The string left complement 0 Method Example _ruby topic in Ruby

Recently there is a need to show the number as a fixed number of digits, the number of digits in the front with 0 supplements

Like 5-bit:

Copy Code code as follows:

3-> 00003
292-> 00292
12422-> 12422

It's easy to find Ruby.

Copy Code code as follows:

Irb> "%05d"% 12422
"12422"
Irb> "%05d"% 22
"00022"

The above approach is basically standard practice. If you are working with strings directly, you can also use String#rjust:
"12422". Rjust (5, ' 0 ') => "12422"
"Rjust" (5, ' 0 ') => "00022"

Attached: Another article

In the project, we used the algorithm of the string to fill zero, and finally found that rails has this function can be implemented, eliminating unnecessary trouble, the example should be very easy to understand

Copy Code code as follows:

>>> A = 22
>>> s = str (a). Rjust (4, ' 0 ')
>>> Print S
0022
>>> A = 2222
>>> s = str (a). Rjust (4, ' 0 ')
>>> Print S
2222