CODEWITHSUNDEEP
javascriptjquerylocal-storage
Jared
Jared

Reputation: 401

How do I check localstorage for a duplicate value?

I have this code here http://jsfiddle.net/so0rL8kj/3/

and I'm having trouble implementing a check of does input already exist in object array.

I've tried looping over json.parse(urls) something like this 

if (this.url == id) {
    console.log("found:  " + JSON.stringify(this));
    $(".order").append("<li>" + id + " ... already exists in your list.</li>");
    return false;
}

But that did not stop the code from executing the localstorage.setitem save. I also tried to save as an array and then using inArray() but had no results with this functionality either.

How do I add a check to stop duplicates from user input for localstorage?

edit: working fiddle http://jsfiddle.net/so0rL8kj/4/

Upvotes: 0

Views: 745

Answers (1)

charlietfl
charlietfl

Reputation: 171669

You can't use $.inArray() to compare a string to an array of objects.

Array would look something like:

[{"url":"someVal"},{"url":"Anotherval"}]

All $.inArray() will do is look at each object, and will never find a match since you are looking for the value of an object property in each element of the array

You can use a for loop to iterate the array and compare each url property to the string or use various array methods like Array.prototype.filter() 

var alreadyExists = arrayCheck.filter(function(item){
    return id ==== item.url
}).length;

This filters the array to objects that match the url to id and if it has no length there is no match

Upvotes: 1

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