var arr = []
    arr.splice()
    arr.reverse()
    arr.fill()
    arr.copyWithin()
    arr.sort()
    arr.push()
    arr.pop()
    arr.unshift()
    arr.shift()

    var arr = []
    arr.slice()
    arr.map()
    arr.forEach()
    arr.every()
    arr.some()
    arr.filter()
    arr.reduce()
    arr.entries()
    arr.find()
    arr.concat('1',['2','3']) //[1,2,3]