I need to write a string that contains only numbers from 0 to 9

Question

So i have this project where i need to write a mutator method that changes a person's phone number only if the phone number contains numbers from 0 to 9 and no letters or any other things. The type of the phone number is string and i tried using conditional statements. If the mobile contains anything other than numbers then nothing should happen. this is what i got so far:

public void setMobile(String mobile) {
if(mobile.matches("[a-zA-z]+")){
 }
 else{      
        this.mobile = mobile;
 }

}

thanks

What is your question? But let me ask you a question: If you want to check is string is all digits (0-9), why not check that, i.e. `matches("[0-9]+")`?\ — Andreas, Apr 04 '17 at 04:52
Possible duplicate of [How to check if a String is numeric in Java](http://stackoverflow.com/questions/1102891/how-to-check-if-a-string-is-numeric-in-java) — soorapadman, Apr 04 '17 at 04:55

score 2 · Accepted Answer · answered Apr 04 '17 at 04:53

2

You regex pattern should be [0-9]+

answered Apr 04 '17 at 04:53

prasanth

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if this is it then the if condition should be reversed right? – Suraj Rao Apr 04 '17 at 04:54
Thanks. that fixed it – Omri Ram Apr 04 '17 at 05:24

score 0 · Answer 2 · answered Apr 04 '17 at 04:59

0

If you are looking for anything that isn't a number then the pattern is \D. That just means non-digit and is a shorthand for [^0-9]

See http://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html

answered Apr 04 '17 at 04:59

sprinter

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I need to write a string that contains only numbers from 0 to 9

2 Answers2