TypeError: arr.slice is not a function in nodejs

Asked Jul 09 '20 at 11:34

Active Jul 09 '20 at 11:42

Viewed 236 times

I'm trying to do arr.slice and convert it to json for get request but I get error TypeError: arr.slice is not a function

const splitArray = (req, res, arr = shuffled, n = 4) => {
    if (n < 2) {
        return arr
    }
    let size;
    let result = [];
    for (let i = 0; i < arr.length; i++) {
        if (arr.length % n === 0) {
            size = arr.length / n
            while (i < arr.length) {
                result.push(arr.slice(i, i += size))
            }
        } else {
            while (i < arr.length) {
                size = Math.floor(arr.length / n)
                result.push(arr.slice(i, i += size))
            }
        }
    }
    JSON.stringify({ result }).then((result) => res.send({ result })).catch()
}

app.get('/cards', splitArray)

asked Jul 09 '20 at 11:34

Mahmoud Nafea

Might by any change, `arr` be a string and not an array? What does the console say if you dump out `arr`? – Johannes Klauß Jul 09 '20 at 11:37
3

What is the value of `arr` at runtime ? – Seblor Jul 09 '20 at 11:37
1

@JohannesKlauß `String.prototype` also has [`slice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice) – adiga Jul 09 '20 at 11:42
You've set `arr = shuffled`, what is the value/type of shuffled? – Dane Brouwer Jul 09 '20 at 11:44
@DaneBrouwer `shuffled` is just the default param, but he uses it with `app.get` so that param gets populated by the framework. – Johannes Klauß Jul 09 '20 at 11:47
shuffled is an array of arrays. when I console.log('arr',arr) I get nothing it doesn't appear in the terminal – Mahmoud Nafea Jul 09 '20 at 11:49
Is this using Express? If it is express, the framework will not correctly populate the array as the function should follow the following pattern `req, res, next`. – Dane Brouwer Jul 09 '20 at 11:50
when I removed req,res from the function and console.log(arr) it appears as array. so the issue how to read my function in the get request – Mahmoud Nafea Jul 09 '20 at 11:53
Have you tried using the parsed request body? – Dane Brouwer Jul 09 '20 at 11:56
how to do it here in get request? – Mahmoud Nafea Jul 09 '20 at 11:58
Does this answer your question? [How to access body in express.js GET request?](https://stackoverflow.com/questions/37339715/how-to-access-body-in-express-js-get-request) – Dane Brouwer Jul 09 '20 at 12:01
@DaneBrouwer unfortunately no – Mahmoud Nafea Jul 09 '20 at 12:07

TypeError: arr.slice is not a function in nodejs

0 Answers0