Javascript 比较索引与数组值

Question

I have a main array, and an object that contains an array of items. I want to see if the object that contains items matches the main array index. If a match, then write to the console.

var mainItems = [0,1,2,3,4,5,6,7,8,9,10,"car", "boat", "truck", "plane"];
var nonStandardItems =
{
    "items": [
        {

            "value": "8",
            "code": "8ic"
        },
        {
            "value": "boat",
            "code": "10bt"
        }
    ],

}

if( nonStandardItems.items.slice(-1)[0].value == mainItems.indexOf(nonStandardItems.items.slice(-1)[0].value)  ){
    console.log("you are right");
}

However, I only get a value of -1, and an error. What am I missing?

EDIT I am pulling data from a different data sources, all containing junk data. However, the last item in the junk data array is the item I need.

I want to check if the results from my api request match an "expected" or "standard" set of data. For example, my nonStandardItems object is an example of what I get back from the api.

I want to parse it, and check to see if the LAST item in the items array has a value that matches the index of my standard items array. My junk items array contains numeric and text data, but the last item will always have either a numerical or textual code that I expect.

The example was contrived and rushed, so I apologize for the spelling, syntactical and explanation mistakes. The error the console threw was that nonstandardItems.items[-1].value did not exist.

Answer 1

Use filter():

if (nonStandardItems.items.filter(v => mainItems.indexOf(v.code) == v.value).length > 0) {
    console.log("you are right")
}