~~~ /** * 截取数组长度 * @param arr 数组 * @param n1 开始数组元素 * @param n2 结束数组元素 默认为数组的长度 * @returns {Array} 返回截取的新数组 * * getArrayNum([0,1,2,3,4,5,6,7,8,9],5,9) * [5, 6, 7, 8, 9] * * getArrayNum([0,1,2,3,4,5,6,7,8,9],2) * [2, 3, 4, 5, 6, 7, 8, 9] * */ function getArrayNum(arr, n1, n2) { let arr1 = [], len = n2 || arr.length - 1; for (let i = n1; i <= len; i++) { arr1.push(arr[i]) } return arr1; } ~~~