str.to_i(base=10)   → integer

Returns the result of interpreting leading characters in str as an integer base base (2, 8, 10, or 16). Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0 is returned. This method never raises an exception.

"12345".to_i             #=> 12345
"99 red balloons".to_i   #=> 99
"0a".to_i                #=> 0
"0a".to_i(16)            #=> 10
"hello".to_i             #=> 0
"1100101".to_i(2)        #=> 101
"1100101".to_i(8)        #=> 294977
"1100101".to_i(10)       #=> 1100101
"1100101".to_i(16)       #=> 17826049

Source Code

/*
*  call-seq:
*     str.to_i(base=10)   => integer
*  
*  Returns the result of interpreting leading characters in <i>str</i> as an
*  integer base <i>base</i> (2, 8, 10, or 16). Extraneous characters past the
*  end of a valid number are ignored. If there is not a valid number at the
*  start of <i>str</i>, <code>0</code> is returned. This method never raises an
*  exception.
*     
*     "12345".to_i             #=> 12345
*     "99 red balloons".to_i   #=> 99
*     "0a".to_i                #=> 0
*     "0a".to_i(16)            #=> 10
*     "hello".to_i             #=> 0
*     "1100101".to_i(2)        #=> 101
*     "1100101".to_i(8)        #=> 294977
*     "1100101".to_i(10)       #=> 1100101
*     "1100101".to_i(16)       #=> 17826049
*/

static VALUE
rb_str_to_i(argc, argv, str)
   int argc;
   VALUE *argv;
   VALUE str;
{
   VALUE b;
   int base;

   rb_scan_args(argc, argv, "01", &b);
   if (argc == 0) base = 10;
   else base = NUM2INT(b);

   if (base < 0) {
       rb_raise(rb_eArgError, "illegal radix %d", base);
   }
   return rb_str_to_inum(str, base, Qfalse);
}