[Vuejs]-Vue.js array in object from db is undefined, even though the values appear in console

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It is happening because in some of the data objects, tree property is missing. Hence, when you trying to access nodes or edges objects it is giving you the below error.

TypeError: Cannot read properties of undefined (reading ‘nodes’)
TypeError: Cannot read properties of undefined (reading ‘edges’)

You can resolve this by using Optional Chaining (?.) operator.

console.log(tree?.nodes)
console.log(tree?.edges)

Live Demo :

const datas = [{
  'id' : "aeENkvQdx",
  'tree': {  
    'nodes' : [{ 'node_id': 0, 'text': 'test'}],
    'edges' : [{ 'node_id': 0, 'text': 'test'}]
  }

}, {
  'id' : "aeENkdYJh"
}];

datas.forEach(function(data) {
  var tree = data.tree;
  console.log(tree);
  console.log(tree?.nodes);
});

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