数组求和

计算数组的和.js

/**
 * Created by Godfery on 2016/12/8.
 */
/**
 * Created by Godfery on 2016/12/7.
 */
var a = [['bj', 1, 'sh', 2, 'wh', 3], ['gz', 4, 'bj', 5], ['sh', 6], ['sh', 5]];
/**
 * 获取数组聚合
 * @param array
 * @return {*}
 */
function getAggregation(array) {
    var key, value;
    return array.reduce(function (all, map, index) {
        map.forEach(function (key, i) {
            if (i % 2 === 0) {
                value = map[i + 1];
                all.push([key, value]);
            }
        });
        return all;
    }, []).reduce(function (count, arr) {
        key = arr[0];
        value = arr[1];
        if (!count[key]) {
            count[key] = 0;
        }
        count[key] += value;
        return count;
    }, {});
}

getAggregation(a);

/**
 * 获取求和数组
 * @param arrays
 * @return {Array}
 */
function getCountArray(arrays) {
    arrays = arrays.reduce(function (strs, array) {
        strs.push(array.join(','));
        return strs;
    }, []).join(',').split(',');
    var countMap = arrays.reduce(function (count, arr, i) {
        if (i % 2 === 0) {
            var key = arrays[i],
                value = +arrays[i + 1];
            if (!count[key]) {
                count[key] = 0;
            }
            count[key] += value;
        }
        return count;
    }, {});

    return Object.keys(countMap).map(function (key) {
        return [key, countMap[key]];
    });
}
getCountArray(a);