CODEWITHSUNDEEP
javascriptphphtmlcss
Nadim Iqbal
Nadim Iqbal

Reputation: 103

How to Validate Input in JavaScript?

I am trying to validate a input field. The input field should take only numbers, if not it will alert "input must be a number". And if the field is empty it will do nothing. But when I left the field empty it will aslo alert me. How can I fix this. Here is my code

<div class="form-group">
<label class="col-lg-2 control-label">Gross Salary</label>
<div class="col-lg-8">
<input class="form-control" placeholder="Gross Salary" type="text"      name="gross_salary"id="tax4">
</div>
</div>

and javascript code

<script type="text/javascript">
    var validate_int_taxid = function() {
    var tax = document.getElementById("tax4");
    var tax_id = parseFloat(tax.value);
    if (isNaN(tax_id)) {
        alert("Gross Salary  must be a Number");
        return false;
    }
    return true;
}
</script>

Thank You

Upvotes: 0

Views: 95

Answers (3)

Jenz
Jenz

Reputation: 8369

Try with this.

<script type="text/javascript">
    var validate_int_taxid = function() {
    var tax = document.getElementById("tax4");
    if(tax.value!="" )
    {
    var tax_id = parseFloat(tax.value);

    if (isNaN(tax_id)) {
        alert("Gross Salary  must be a Number");
        return false;
    }
    }
}
</script>

Upvotes: 0

Tamura
Tamura

Reputation: 1798

Here you go:

<script type="text/javascript">
var validate_int_taxid = function() {
    if (tax.value !="") {
        var tax_id = parseFloat(tax.value);
        if (isNaN(tax_id)) {
            alert("Gross Salary  must be a Number");
            return false;
        }
        return true;
    } 
    return false;
}
</script>

Upvotes: 0

Mithun Satheesh
Mithun Satheesh

Reputation: 27835

make it like

var tax = document.getElementById("tax4");

if(tax.value!="") {
    var tax_id = parseFloat(tax.value);
    if (isNaN(tax_id)) {
       alert("Gross Salary  must be a Number");
       return false;
    }
    return true;
} else {

    return false;
    //do nothing

}

Here is a fiddle.

Upvotes: 2

Related Questions