How to restrict number of characters that can be entered in HTML5 number input field on iPhone

Example

JS

function limit(element)
{
    var max_chars = 2;
         
    if(element.value.length > max_chars) {
        element.value = element.value.substr(0, max_chars);
    }
}

HTML

<input type="number" onkeydown="limit(this);" onkeyup="limit(this);">

If you are using jQuery you can tidy up the JavaScript a little:

JS

var max_chars = 2;
    
$('#input').keydown( function(e){
    if ($(this).val().length >= max_chars) { 
        $(this).val($(this).val().substr(0, max_chars));
    }
});
    
$('#input').keyup( function(e){
    if ($(this).val().length >= max_chars) { 
        $(this).val($(this).val().substr(0, max_chars));
    }
});

HTML

<input type="number" id="input">