CODEWITHSUNDEEP
javascriptarrays
MazMat
MazMat

Reputation: 2094

Can't push object to array

I have this simple code 

let pathFinder = (entranceX, entranceY, grid) => {
            let distanceFromTop = entranceX;
            let distanceFromLeft = entranceY;

            let location = {
                distanceFromTop: distanceFromTop,
                distanceFromLeft: distanceFromLeft,
                path: [],
                status: 'Start'
            }


            console.log('start', location)

            let queue = [];
            queue.push(location);
            console.log('queue', queue)
}

And I made sure that "location" is not empty, it shows just fine in the console as:

"start {distanceFromTop: 1, distanceFromLeft: 0, path: Array(0), status: "Start"}"

but when I want to add it to the queue I end up with something that doesnt look like an empty array, but the length is 0

"queue [{…}] length :0"

Am i missing something obvious? Tried to add it via queue[location] but it also didnt work

Upvotes: 0

Views: 4079

Answers (2)

Rohith Murali
Rohith Murali

Reputation: 5679

Looks like the push is working but the array is not being displayed while logging the whole object 

queue.push(location);
console.log("queue", queue[0]);

queue {distanceFromTop: 1, distanceFromLeft: 1, path: Array(0), status: "Start"}

And if you change the console as,

console.log("queue", Array.from(queue));

You can see the contents of the array too.

Upvotes: 1

Lucy Isabelle
Lucy Isabelle

Reputation: 98

You should check up on the difference between let and var

var pathFinder = (entranceX, entranceY, grid) => {
        var distanceFromTop = entranceX;
        var distanceFromLeft = entranceY;

        let location = {
            distanceFromTop: distanceFromTop,
            distanceFromLeft: distanceFromLeft,
            path: [],
            status: 'Start'
        }


        console.log('start', location)

        var queue = [];
        queue.push(location);
        console.log('queue', queue)
}

Let can only be used in the scope block in which it’s declared where as var is throughout the function it is declared or globally. Changing the first three (the function and the two distance as well as the queue) variables to var should fix this for you. If not changing them all definitely would.

Upvotes: 1

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