把数组中数组第二个值为0的替换为相邻不为0的值

var a = [
    ['2023-04-01', 0],
    ['2023-04-02', 0],
    ['2023-04-03', 3],
    ['2023-04-04', 0],
    ['2023-04-05', 5],
    ['2023-04-06', 0],
    ['2023-04-07', 0],
    ['2023-04-08', 0],
    ['2023-04-09', 0],
    ['2023-04-10', 10],
    ['2023-04-11', 0],
    ['2023-04-12', 0],
]
// 把数组中数组第二个值为0的替换为相邻不为0的值
function fn(a){
    for(var i=0; i<a.length; i++) {
        for(let j=i+1; j<a.length; j++){
            if(a[j][1] !== 0 && a[i][1] == 0) {
                a[i][1] = a[j][1]
            }
        }
        for(let k=a.length-1; k>1; k--){
            // console.log(a[k][1]);
            if(a[k][1] !== 0 && a[i][1] == 0) {
                a[i][1] = a[k][1]
            }
        }
    }
}
fn(a)
console.log(a);

返回结果

[  [ '2023-04-01', 3 ],
  [ '2023-04-02', 3 ],
  [ '2023-04-03', 3 ],
  [ '2023-04-04', 5 ],
  [ '2023-04-05', 5 ],
  [ '2023-04-06', 10 ],
  [ '2023-04-07', 10 ],
  [ '2023-04-08', 10 ],
  [ '2023-04-09', 10 ],
  [ '2023-04-10', 10 ],
  [ '2023-04-11', 10 ],
  [ '2023-04-12', 10 ]
]