CODEWITHSUNDEEP
javascriptarraysif-statement
tokyo_tech
tokyo_tech

Reputation: 13

I have an If statement that is not working, yet is logically correct

if ("tester" == findrange[117])
{
  var indict = 34;
}
if (keeperval[39] == "tester")
{
  var indict2 = 45;
}
if (keeperval[39] == findrange[117])
{
  var indict3 = 56;
}

This code will return when debugging will return these values:

indict = 34

indict2 = 45

indict3 = undefined

Does this make any sense? I just can't wrap my head around why this possibly wouldn't work!

Upvotes: 0

Views: 49

Answers (4)

Zeta
Zeta

Reputation: 105885

You probably wrapped your strings in findrange[117] and keeperval[39] in String, instead of simply using a literal.

Therefor, both aren't strings, but instead string objects. When you use them in a comparison with strings, it will use the object's .toString(), therefor == "tester" will work.

However, when both sides of an equality comparison are objects, the result will be true if and only if both objects are actually the same:

var s1 = new String("test");
var s2 = new String("test");
console.log(s1 == s2); // logs false

So instead of 

findrange[117] = new String("tester");
keeperval[39] = new String("tester");

use

findrange[117] = "tester";
keeperval[39] = "tester";

Even better, exchange your equality tests with type-safe equality tests:

if ("tester" === findrange[117])
{
  var indict = 34;
}
if (keeperval[39] === "tester")
{
  var indict2 = 45;
}
if (keeperval[39] === findrange[117])
{
  var indict3 = 56;
}

Then you will see instantly that there's something off. (fiddle)

For further reference, see MDN's JavaScript guide, especially sameness in JavaScript.

EDIT: If you're not able to change the type of the values in your arrays, use the .toString() method before comparing:

if ("tester" === findrange[117].toString())
{
  var indict = 34;
}
if (keeperval[39].toString() === "tester")
{
  var indict2 = 45;
}
if (keeperval[39].toString() === findrange[117].toString())
{
  var indict3 = 56;
}

Upvotes: 3

Faiz Mohamed Haneef
Faiz Mohamed Haneef

Reputation: 3596

First check the type console.log(typeof(findrange[117]));

In your case this should be an object

In JS,

compare obj to string; will compare obj.value to string value

compare obj to obj; will compare references to the object and not value

Upvotes: 0

Daniel Wondyifraw
Daniel Wondyifraw

Reputation: 7723

try groovy console :

def findrange = ["tester","nontester"]

def keeperval = ["tester"]

if ("tester" == findrange[0])
{
  def indict = 34;
println indict

}
if (keeperval[0] == "tester")
{
  def indict2 = 45;
println indict2
}
if (keeperval[0] == findrange[0])
{
  def indict3 = 56;

  println indict3

}

output : 34 45 56

Upvotes: 0

rvandoni
rvandoni

Reputation: 3407

use

keeperval[39] === findrange[117]

to understand if both of them are objects or strings.

Upvotes: 0

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