function compose(arr, level, stringBuffer) {
for(let i = 0; i< arr[level].length; i++) {
if(level !== arr.length-1) {
compose(arr, level+1, stringBuffer+ arr[level][i])
} else {
console.log(stringBuffer+ arr[level][i])
}
}
}
var arr = [[1,2,3],[4,5,6],[7,8,9]]
for(let i = 0; i< arr[level].length; i++) {
if(level !== arr.length-1) {
compose(arr, level+1, stringBuffer+ arr[level][i])
} else {
console.log(stringBuffer+ arr[level][i])
}
}
}
var arr = [[1,2,3],[4,5,6],[7,8,9]]
compose(arr, 0, '')
输出 147 148 149 157 158 159 167 168 169 247 248 249 257 258 259 267 268 269 347 348 349 357 358 359 367 368 369
var arr = [['a','b'],['c','d','e']]
compose(arr, 0, '')
输出 ac ad ae bc bd be