【Answer】Solution: First, based on "Ding: There is no one to my right," we can conclude that Ding is at position 4;
Then, according to "Jia: The people on both sides of me are taller than me. Yi: The people on both sides of me are shorter than me," we know that both Jia and Yi have people on both sides, so Bing is at position 1;

Since Bing is the tallest, he is taller than the person at position 2, and Jia fits this characteristic, so Jia is at position 2;
The remaining Yi is at position 3;
In summary: The 4-digit number formed by the positions of Jia, Yi, Bing, and Ding in order is 2314.
Therefore, the answer is: 2314.
2. (8 points) Four people, A, B, C, and D, stand in a row, numbered from left to right as $1, 2, 3, 4$. They have the following conversation:
A: The people on both my left and right are taller than me.
B: The people on both my left and right are shorter than me.
C: I am the tallest.
D: There is no one to my right.
If all four of them are honest good children, then the 4-digit number formed by the numbers of A, B, C, and D in order is