Question

Check if atleast one field is not empty in PHP

is very equal to this question. This is just how to do it in javascript.

When you click on #submit it should check atleast one of these fields:

input[name=weight], input[name=size_1], input[name=size_2], input[name=size_3]

are filled, and not empty. If all of them are empty, it should alert(“Please fill one of the fields”)

Update: forgot to mention that if the fields are 0 it should not be counted as filled.

How can i do this? I tried copy over from php, but i get stuck on the foreach loop

Answer 1

You could do this very easily with the filter method:

var filledFields = $('input[name=weight], input[name=size_1], input[name=size_2], input[name=size_3]')
    .filter(function() {
        return !!this.value && this.value !== '0'; // remove if value is empty or 0, keep otherwise
    });

if (filledFields.length) {
    // at least one element has a value set
} else {
    // no fields have values set
    alert("Please fill one of the fields")
}

What this does:

1. Selects all the elements you want to check
2. Runs the filter method: if you return true, the element will be kept; if you return false, it will be removed from the selection
   • !!this.value is true if the value is a non-empty string and otherwise is false
3. We then check the length property of the selection. If it is not 0, at least one element has a non-empty value. If it is 0, they are all empty.

See:

• filter
• length