Check if the first character is a zero, if so replace it with 234. Note that the string replace method only will replace the first occurrence by default.
$( '#button' ).click(function() {
var nr = $( '#nr' ).val();
nr = nr.indexOf('0') == 0 ? nr.replace('0','234') : nr;
$( '#result' ).html(nr);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="nr" />
<button type="button" id="button">Get</button>
<div id="result"></div>
2
solved Mobile number format [closed]