SOURCE

function filter(arr, callback) {
    if (!Array.isArray(arr) || !arr.length || typeof callback !== 'function') {
        return []
    }
    let rec = []
    for (let i = 0; i < arr.length; i++) {
        if(callback(arr[i], i, arr)) {
            rec.push(arr[i])
        }
    }
    return rec
}

function fn(value, idx, arr) {
    return value >=5
}

let arr = [...Array(10).keys()]

console.log(filter(arr, fn))