How to do validate String using regular expression in java

Question

Here i want to make regx for string which contains only 0 to 6 numbers only. This String contains 0 to 6 numbers like that.

 Example-1 : "010002030405" Valid String

This String contains only o to 6 numbers so here i used this regx "[0-6]*". But one more thing i want to validate in this string, I want 0 only at odd positions 1-6 will not be on odd positions never. 0 can be place on odd and even both but 1-6 will be place only even positions.

Here i given u some valid and invalid string examples

Valid : 000102000004
invalid : 0023015006

Here i used this code Please suggest me or tell me what i have to change in my regx to satisfy below validation

1) String contains only 0-6 numbers nothing else.
2) 1-6 would be only even positions only they would not be at odd position ever, 0 would be odd and even position.

Code :

public boolean isOptions(String input) {
    String patternString = "[0-6]*";
    Pattern pattern = Pattern.compile(patternString);
    return pattern.matcher(input).matches();
}

"I want 0 only at odd positions 1-6 will not be on odd positions never. 0 can be place on odd and even both" Isn't this a bit contradictory that you want 0 only at odd positions and that 0 can be placed at both odd and even? — Hyperboreus, Dec 10 '12 at 05:39
are you really bent upon using regex here? I think simple loop and checking should be much easier here. — vishal_aim, Dec 10 '12 at 05:41
@Hyperboreus Sorry my bad. i want 0 at even and odd both and 1-6 only on even places. — sam_k, Dec 10 '12 at 06:24
http://stackoverflow.com/questions/691519/regular-expression-to-match-only-odd-or-even-number This would help lot to achieve the logic you trying to build — Dinesh Prajapati, Dec 10 '12 at 05:53

score 7 · Accepted Answer · answered Dec 10 '12 at 05:41

7

Haven't tried this out, but might work:

(0[0-6])*0?

answered Dec 10 '12 at 05:41

Hyperboreus

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how is it ensuring that 1-6 are only at even positions? – vishal_aim Dec 10 '12 at 05:45
3

Because first comes a 0 and then anything between 0 and 6. Rinse and repeat (this pattern of 2 digits). Then maybe add a final 0. – Hyperboreus Dec 10 '12 at 05:46
@Hyperboreus Thanks Can u please Explain me this regular expresssion – sam_k Dec 10 '12 at 06:33
This expression matches all strings that have 0 or more times a couple of "0" follow by a digit between 0 and 6; and maybe a trailing 0. – Hyperboreus Dec 10 '12 at 06:37
@Hyperboreus Here i want to check String validation for every 2 places. So what type of modification i have to make change? – sam_k Dec 21 '12 at 04:39
Could you explain this in more detail or open a new question? – Hyperboreus Dec 21 '12 at 06:20

How to do validate String using regular expression in java

1 Answers1