Regular Expression for number only

Question

I use [0-9] expression to validate text field have number only.
If you write abc 900 so it gives error, but i you write 900 abc , it gives no error.
What's correct regular expression for number only
Please help.

Answer 1

What message "never remove"?
How do you handling your input validation? in which context?
If you are validating inputs from html <input> through the attribute pattern, you can do the behavior you describe: show/hide an error message... suppose you have:
<label>Choose a number:</label><br>
<input type="text" pattern="^\d+quot;><br>
<label>error message</label>
input+br+label {
opacity:0;
color:red;
}
input:invalid+br+label {
opacity:1;
}
However, you can use the <input type="number"> for this special case ;)
... If you handle regexp in html form context... but you don't specify :P

Answer 2

^\d+$ or ^[0-9]$

Answer 3

Thank you its work with ^[0-9]*$

Answer 4

IIya, now it shows validation message but if user correct it the error message never remove