I have the following in javascript:
var colors = ["dark", "light"];
if (localStorage.themeColor) {
How can I modify this to not only check that localStorage.themeColor is set but also to check that it is one of the two values in the array?
6 Answers
You can use indexOf in conjunction with your existing check for themeColor:
if(localStorage.themeColor && colors.indexOf(localStorage.themeColor) > -1) {
// Do stuff
}
Comments
You can say something like:
var colors = ["dark", "light"];
if (localStorage.themeColor && colors.indexOf(localStorage.themeColor) != -1) {
For indexOf see:
1 Comment
CodingIntrigue
This won't work. You've got an error in your indexOf check and your missing closing parenthesis
for(var i=0;i<colors.length;i++)
{
if(localStorage.themeColor==colors[i])
{
alert(colors[i]);
}
else{
alert("colors not set");
}
Comments
colors.indexOf("dark") !== -1
indexOf returns -1 if the argument passed does not exist in colors
Comments
You can solve it like this
var colors = ["dark", "light"];
if (localStorage.themeColor && colors.indexOf(localStorage.themeColor) > -1) {
// Your Code...
}
I tested it in the case of localStorage.themeColor == light and localStorage.themeColor is undefined
Comments
you should create a prototype like this
Array.prototype.contains = function(elem)
{
for (var i in this)
{
if (this[i] == elem) return true;
}
return false;
}
And your array here
var colors = ["dark", "light"];
Finally call the function using colors.contains("dark") // this will return true
3 Comments
CodingIntrigue
Sorry, I had to downvote this because you're basically rewriting an existing function.
Ajey
existing function you mean contains() ?
CodingIntrigue
No, indexOf (as linked to in multiple answers here) does exactly this