Is there any difference between the three ways of writing in the regular expression []?

1[0-9a-zA-Z]
2[0-9,a-z,A-Z]
3[0-9|a-z|A-Z]

is there any difference between these three ways of writing? It seems to mean either numbers, lowercase letters, or uppercase letters. -sharp-sharp-sharp problem description

Jun.09,2021

  1. the first matching numeric uppercase and lowercase letters
  2. the second matches numbers, uppercase and lowercase letters,
  3. the third one also matches numbers, uppercase and lowercase letters, and |

1, [0-9a-zA-Z]

var reg = /[0-9|a-z|A-Z]/g;
reg.test('|'); // true
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b2af60-2b2ac.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b2af60-2b2ac.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?