JavaScript Check multiple variables being empty

Question

I'm trying the following code:

var var1 = "";
var var2 = "test";
var var3 = "";

vars = new Array('var1','var2','var3');

var count = 0;

for (var i = 0; i < vars.length; ++i) {
    var name = vars[i];
    if (field_is_empty(name)) {
        count++;
    }
}

console.log(count);

function field_is_empty(sValue) {
    if (sValue == "" || sValue == null || sValue == "undefined")
    {
        return true;
    }
    return false;
}

The result here should have been count = 2 because two of the variables are empty but it's always 0. I guess it must something when using if (field_is_empty(name)) because it might not getting the name converted to the name of the actual var.

PROBLEM 2# Still related

I've updated the code as Karthik Ganesan mentioned and it works perfectly.

Now the code is:

var var1 = "";
var var2 = "test";
var var3 = "";

vars = new Array(var1,var2,var3);

var count = 0;

for (var i = 0; i < vars.length; ++i) {
    var name = vars[i];
    if (field_is_empty(name)) {
        count++;
    }
}

console.log(count);

function field_is_empty(sValue) {
    if (sValue == "" || sValue == null || sValue == "undefined")
    {
        return true;
    }
    return false;
}

And the problem is that if add a new if statement something like this:

if (count == '3') {
    console.log('AllAreEmpty');
} else {
    for (var i = 0; i < vars.length; ++i) {
        var name = vars[i];
        if (field_is_empty(name)) {
            //Set the empty variables as "1900-01-01"
            variableService.setValue(name,"test");
        }
    }
}

It does nothing and I've tested using variableService.setValue('var1',"test") and it works.

PS: The variableService.setValue is a function controlled by the software I don't know exactly what it does I know if use it like mentioned on above line it works.

It's because you're not passing the content of each variable, but rather the name of it. For example, you're doing field_is_empty('var1'), not field_is_empty(""). You simply need to remove the quotation marks from your array. — Tyler Roper
– Tyler Roper, Commented Dec 16, 2016 at 18:01
You're not properly putting your variables into your array. Look closer at what you're doing, which is putting a string of the variable name, but not the variable itself. Remove the quotes for starters. — Waxi
– Waxi, Commented Dec 16, 2016 at 18:01

Lajos Arpad · Accepted Answer · 2016-12-16 19:03:25Z

In your first attempt you used the variable names as strings when you created an array. You need to either use the values themselves:

vars = new Array(var1,var2,var3);

or if you insist to use them by their names, then you need to find them by names when you use them:

if (field_is_empty(window[name])) {

It does nothing

That's not really possible. It could throw an error, or enter the if or enter the else, but doing nothing is impossible. However, since you intended to use the variables by name in the first place (probably not without a reason) and then you intend to pass a name, but it is a value and it does not work as expected, I assume that your initial array initialization was correct and the if should be fixed like this:

var var1 = "";
var var2 = "test";
var var3 = "";

vars = new Array(var1,var2,var3);

var count = 0;

for (var i = 0; i < vars.length; ++i) {
    var v = window[vars[i]]; //You need the value here
    if (field_is_empty(v)) {
        count++;
    }
}

console.log(count);
if (count == '3') {
    console.log('AllAreEmpty');
} else {
    for (var i = 0; i < vars.length; ++i) {
        var v = window[vars[i]];
        if (field_is_empty(v)) {
            //Set the empty variables as "1900-01-01"
            variableService.setValue(vars[i],"test");
        }
    }
}

function field_is_empty(sValue) {
    if (sValue == "" || sValue == null || sValue == "undefined")
    {
        return true;
    }
    return false;
}

Yuriy Tseretyan · Accepted Answer · 2016-12-16 18:03:06Z

1

You definitely incorrectly initialize array, you put strings "var1", "var2", "var3" instead of references to strings (variables). Try this:

vars = new Array(var1,var2,var3);

answered Dec 16, 2016 at 18:03

Yuriy Tseretyan

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Comments

Karthik Ganesan · Accepted Answer · 2016-12-16 18:01:58Z

0

Your array is wrong

it should be

vars = new Array(var1,var2,var3);

here is the jsfiddle

answered Dec 16, 2016 at 18:01

Karthik Ganesan

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5 Comments

rgomez Over a year ago

That worked ok but it created me another problem, if you could please take a look at edit. Anyhow thanks for your tip.

Karthik Ganesan Over a year ago

where are you adding this "if" condition?

rgomez Over a year ago

Right before function field_is_empty

Karthik Ganesan Over a year ago

by the way you said try something like this to see if it works variableService.setValue("'"+name+"'","test");

Karthik Ganesan Over a year ago

sorry i just saw you need the variable name

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