[JS] 배열 - 두 배열 합치기, 배열 평탄화, 배열 분할

/**
* 두배열 합치기
* [{A : 1}] + [{B : 1}] = [{A : 1, B : 1}]
*/
function assignArrObj (a, b){
    if(a.length > b.length){
        a.forEach(function(v, i){
          b.forEach(function(v2, i2){
            if(i == i2)
                Object.assign(v, v2)
          });
        });
      }else{
        b.forEach(function(v, i){
          a.forEach(function(v2, i2){
            if(i == i2)
                Object.assign(v, v2)
          });
        });
      }
      return a.length > b.length ? a : b;
}

/*
    * 배열 merge n차원 평탄화
    * [ [{a : 1 }], [{a : 2 }]] -> [{a : 1 } , {a : 2 }]
    */
1.
    function fc_flatten(arr) {
      return arr.reduce(function (flat, toFlatten) {
        return flat.concat(Array.isArray(toFlatten) ? fc_flatten(toFlatten) : toFlatten);
      }, []);
    }

/*
* 배열 merge 1차원 평탄화
*/
var merged = [].concat.apply([], arrays);






/*
*  [[{a : '1'}, {a:'2'}],[{a:'3'}]] -> [["[object Object]", "[object Object]", "[object Object]"]
*  [[1,2,3],[4,5]]  -> ["1", "2", "3", "4", "5"]
*/
var arr = [[{a : '1'}, {a:'2'}],[{a:'3'}]];
1.
var newArr = arr.toString().split(',');
2.
var newArr = arr.flat(1)

/*
* 배열 n 개만큼 잘라 새 배열 만들기
*/
function fc_divisionArray(dataArray, size){
        const length = dataArray.length;
        const divide = Math.floor(length / size) + (Math.floor( length % size ) > 0 ? 1 : 0);
        const newArray = [];
        
        for (let i = 0; i <= divide; i++) {
            // 배열 0부터 n개씩 잘라 새 배열에 넣기
            newArray.push(dataArray.splice(0, size));
        }
        
        return newArray;
    }