One common use of regular expressions is to determine if an input is valid. In this example, we determine if a string is a valid Social Security Number.
In the United States, a Social Security has this format: XXX-XX-XXX. So we will use this pattern to determine validity: ^\d{3}-\d{2}-\d{4}$.
First off we’ll create our input. In this case it will just be an array that we loop through.
1
2
3
4
var input;
input[0] = "111-22-3333";
input[1] = "111-2-3333";
input[2] = "11-22-3333";
Now we can create our regex, loop through the input, and output whether the SSN was formatted correctly.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
var input;
input[0] = "111-22-3333";
input[1] = "111-2-3333";
input[2] = "11-22-3333";
var regex = regex_create("^\d{3}-\d{2}-\d{4}$", RO_NONE, 3000);
for(var i = 0; i < array_length_1d(input); i++)
{
if(regex_is_match(regex, input[i]))
{
show_debug_message(input[i] + " is a valid SSN");
}
else
{
show_debug_message(input[i] " is not a valid SSN");
}
}
// Output:
// 111-22-3333 is a valid SSN
// 111-2-3333 is not a valid SSN
// 11-22-3333 is not a valid SSN