Javascript Ceil Increments

Question

I currently have this which rounds up any input number to the nearest whole value on blur:

$(function(){
    $('#my_value').blur(function() {
    $(this).val(Math.ceil($(this).val()));
    });
});

The problem is I need it to round to the next nearest 1/10th, so if someone input 1.23 it would round up to 1.3. Or if someone input 3.78 it would round up to 3.8.

Additionally I'd like it to display an alert when a value above 9 is entered into the #my_value field.

Thanks in advance.

Answer 1

@LinusKleen has what you want:

var num = + $(this).val(); 
if (num > 9) {
  alert('message');
} else {
  $(this).val(Math.ceil(num * 10) / 10);
}

Answer 2

Try something like this

function nearest(value, min, max, steps){
    var zerone = Math.round((value-min)*steps/(max-min))/steps; // bring to 0-1 range
    return zerone*(max-min) + min;
}


console.log(nearest(2.75, 0, 10, 10)); // 3
console.log(nearest(5.12, 5, 6, 10)); // 5.1
console.log(nearest(0.06, 0, 1, 10)); // 0.1


$('#my_value').blur(function() {

if($(this).val() >9 )
{
alert("message");

}
else
nearest($(this).val(),0,9,10);

});

or try below

if val= 28.45 means

Math.round($(this).val()*10)/10  //returns 28.5