Question

a=[[a,b,c],[a,d,e][b,c,d]],JS把二维数组内每个数组第一个相等的数组合并

a=[[a,b,c],[a,d,e][b,c,d]],JS把二维数组内每个数组第一个相等的数组合并，合并后a=[[a,b,c,d,e],[b,c,d]].怎么写代码？

Answer 1

            var a=[['a','b','c'],['a','d','e'],['b','c','d']];
            var result = [];
            var getIndex = function(result, arr) {
                for (var i = 0; i < result.length; i++) {
                    if (result[i] && result[i][0] == arr[0]) {
                        return i;
                    }
                }
                return -1;
            }
            var merge = function(arr1, arr2) {
                for (var i = 1; i < arr2.length; i++) {
                    arr1.push(arr2[i]);                
                }
            }
            for (var i = 0; i < a.length; i++) {
                var index = getIndex(result, a[i]);
                //console.log(index);
                if (index >= 0) {
                    merge(result[index], a[i]);
                } else {
                    result.push(a[i]);
                }
            }
            return result;