I want to add elements to treetable dynamically.but I can't combine arrays when merging.

const nodes=([]);
const children=([])

then I add an element to the nodes array

 nodes.push({
        key: keyIndex.value,
        data:{
          "name":newExplanation.value,
          "size":"100kb",
          "type":"Folder"

        },
      })

This is how I push on my second string

children.push({
            children:[
              {
                key: tempRoot.value + '-0' ,
                data: {
                  "name": Explanation.value,
                  "size": "100kb",
                  "type": "Folder"

                }
              }]

          })

then I want to add a child node element under this element and I want to combine these two arrays. But they don't get together, they seem like two separate elements in an array. for example nodes[0:{first element}, {second element]

Here's how I do the merge

let r = nodes.concat({...children})