二维数组的排列组合

将二维数组[['a', 'b', 'cd'],['de'],['e', 'f']]处理后输出为['adee', 'adef', 'bdee', 'bdef', 'cddee', 'cddef']

const arr = [['a', 'b', 'cd'],['de'],['e', 'f'],]

const result = arr.reduce((pre,item) => {
    const arr = []
    pre.forEach(item1 => {
        item.forEach(item2 => {
            arr.push(ite1 + item2)
        })
    })
    return arr
})
console.log(result);