Check if name is valid with Proper case and Max one space

Question

I searched for all regex exp but didn't find any matching my needs.

In none of the above did I get a solution:

I need to check that the name is valid if
=> First letter every word should be caps
=> Rest all letters of each word should be small
=> Name should have only alpha char A-Z and a-z
=> First word Length should be min 3
=> Name should not have more than one space between words

Ex :
sujay => false
Sujay => true

Sujay u => false
Sujay U => true

Sujay U n => false
Sujay U N => true

SuJay U => false
Sujay UN => false
Sujay Uls => true

Sujay9 => false
Su => false
Su U => false
Sujay U N => true
Sujay Uls Nat=> true

|*| Check function used :

static boolean chkNamVldFnc(String namVar)
{
    String namRegExpVar = "[A-Z][A-Za-z ]{2,}";

    Pattern pVar = Pattern.compile(namRegExpVar);
    Matcher mVar = pVar.matcher(namVar);
    return mVar.matches();
}

|*| Try 1 :

String namRegExpVar = "[A-Z][A-Za-z ]{2,}";

|*| Try 2 :

String namRegExpVar = "[A-Z][a-z]{2,}+//s[A-Z][a-z]{2,}";

|*| Try 3 :

String NamRegExpVar = "[A-Z][a-z]{2,}||[A-Z][a-z]{2,}+//s[A-Z][a-z]";

Kindly help me with Proper Regular Exp :

I also want to know why we should start Reg Exp with ^ and end with $

`Name shud have only one space`. `Sujay U N => true` this name has two spaces, doesn't it? — Roman Puchkovskiy, Jun 07 '17 at 19:19
Now, `Sujay U` is both *true* and *false* - why? See https://regex101.com/r/tMEQTN/1 — Wiktor Stribiżew, Jun 07 '17 at 19:24
`Rest all letters of each word should be small` -- I disapprove of this regex. — Ian McLaird, Jun 07 '17 at 19:29
In true case U is caps and in false case u is smal. In simple users shud enter only proper case Names — Sujay U N, Jun 07 '17 at 19:29
@SujayUN You should format the test data as code. Multiple spaces got lost in the body. — Wiktor Stribiżew, Jun 07 '17 at 19:37
I was not aware of the website https://regex101.com/ and test data format. Its really helpful and will follow. Thank you for good suggestion. — Sujay U N, Jun 07 '17 at 19:42
@IanMcLaird Ask me about the one where each word has to begin with a capital. — Dawood ibn Kareem, Jun 07 '17 at 19:48

score 2 · Accepted Answer · answered Jun 07 '17 at 19:30

2

Try:

^[A-Z][a-z]{2,}(?: [A-Z][a-z]*)*$

First name must start with letter A-Z, followed by at least 2 letters a-z
Optionally, there can be names following the first name, seperated by a space and beginning with letter A-Z, and followed by optional letters a-z

answered Jun 07 '17 at 19:30

yas

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This is what I was looking for... but Can u explain why we need to use * mark.... Thank you @dave – Sujay U N Jun 07 '17 at 19:32
@dave Did you just copy the regex from my suggestion? – Wiktor Stribiżew Jun 07 '17 at 19:36
@WiktorStribiżew No, I did not see that until just now. We came up with the same regex! – yas Jun 07 '17 at 19:41
1

Why the `^` and `$`? If OP is using the regular expression in any sensible way, these are redundant. – Dawood ibn Kareem Jun 07 '17 at 19:43
@DawoodibnKareem Without those, the text `Sujay u` would match, since the non-capturing group portion of the regex doesn't need to match anything – yas Jun 07 '17 at 19:44
@dave, you are wrong. If used with `.matches()`, anchors are not necessary. It is a pet peeve, not really an issue. – Wiktor Stribiżew Jun 07 '17 at 19:46
No, @dave. `"Sujay u".matches("[A-Z][a-z]{2,}(?: [A-Z][a-z]*)*")` is false. – Dawood ibn Kareem Jun 07 '17 at 19:47
Does that answer match: Sujay U => false ? – sniperd Jun 07 '17 at 19:53
@SujayUN As per your request, I voted on your question. – Dawood ibn Kareem Jun 07 '17 at 20:02
2

While this answer meets the requirements of the question, I feel the need to point out for posterity that there are three users commenting on this thread (under what seem to be their real names), whose names do not match the regex for various reasons. If you came here looking for a regex for a person's name, you have not found one. – Ian McLaird Jun 07 '17 at 20:31

Check if name is valid with Proper case and Max one space

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