如果number小于零且为负数，则将其隐藏

Question

Having the toughest time writing in the function to hide numbers that are equal to or less than zero. Here is the function I want to write it in at:

function isItANumber() {
var increased = parseInt($("#increasedRevenueValue"));

if(isNaN(increased)) {
    $("#increasedRevenueValue").hide();
}

}

Any thoughts? Should I use OR ?

EDIT: Here is the fiddle of my code http://jsfiddle.net/YVcj7/

Answer 1

Try the following, Im taking a guess at what element your using.

function isItANumber() {
    var increased = parseInt($("#increasedRevenueValue").text());

    if(isNaN(increased) || increased <= 0) {
        $("#increasedRevenueValue").hide();
    }
}
isItANumber();
​

Live Demo

And pure js.. because do we really need jQuery for this?

function isItANumber(el) {
    var increased = parseInt(el.innerText);

    if(isNaN(increased) || increased <= 0) {
        el.style.display = 'none';
    }
}
var element = document.getElementById("increasedRevenueValue");
isItANumber(element);

pure js demo​

Answer 2

I think you want

if(isNaN(increased) || increased <= 0){
    $("#increasedRevenueValue").hide();

}

Answer 3

I don't think you can parseInt a jQuery object. I would try parseInt($("#increasedRevenueValue").text()); or parseInt($("#increasedRevenueValue").val()); depending on what #increasedRevenueValue is.

Answer 4

It looks like your function is doing a bit of double duty (getting the value of a field, checking if it is a number, etc.).

First, I would recommend checking that the value is numeric. This question has a very good isNumeric function that you can leverage.

In that case, you just need to do the following:

function isItANumber(value) {
    var value = $("#increasedRevenueValue").val() || $("#increasedRevenueValue").text() //get the value if this is an input field, or fallback on the text otherwise.
    var isNumber = isNumeric(value);
    var isNegative = value < 0;

    if (isNumber && isNegative) {
        $("#increasedRevenueValue").hide();
    }
}

Answer 5

As people have mentioned, if the element is a input field, your 'increased' should be:

var increased = parseInt($("#increasedRevenueValue").val(), 10);

If its a div/span/paragraph or something along those lines it should be.

var increased = parseInt($("#increasedRevenueValue").text(), 10);

Then simply do an if loop.

if(increased =< 0) {
    $("#increasedRevenueValue").hide();
}

Depending on how your use of this function is you might need to consider if $("#increasedRevenueValue").val() is a empty value, paresint will make it into 0.

Answer 6

I am going to assume that $("#increasedRevenueValue") is an input element,

function isItANumber() {
   //change it to $("#increasedRevenueValue").text() if it is div/span
   var increased = parseInt($("#increasedRevenueValue").val(), 10);

   if(isNaN(increased) || increased <= 0) {
       $("#increasedRevenueValue").hide();
   }

}

Answer 7

我会尝试： http : //jsfiddle.net/pratik136/6J7xz/