使用基本 JavaScript 查找嵌套的 object 数据

Question

I want to loop through 600+ array items in an object and find one particular item based on certain criteria. The array in the object is called "operations" and its items are arrays themselves.

My goal is to get the index of operation's array item which has the deeply nested string "Go".

In the sample below this would be the first element. My problem is that I can check if an array element contains "call" and "draw" but I don't know how to test for the nested dictionary "foobar". I only have basic JavaScript available, no special libraries.

 let json = { "head": {}, "operations": [ [ "call", "w40", "draw", { "parent": "w39", "style": [ "PUSH" ], "index": 0, "text": "Modify" } ], [ "call", "w83.gc", "draw", { "foobar": [ ["beginPath"], [ "rect", 0, 0, 245, 80 ], ["fill"], [ "fillText", "Go", 123, 24 ], [ "drawImage", "rwt-resources/c8af.png", ] ] } ], [ "create", "w39", "rwt.widgets.Menu", { "parent": "w35", "style": [ "POP_UP" ] } ], [ "call", "w39", "draw", { "parent": "w35", "style": [ "POP_UP" ] } ] ] }; let index = ""; let operationList = json.operations; for (i = 0; i < operationList.length; i++) { if (operationList[i].includes('call') && operationList[i].includes('draw')) //missing another check if the dictionary "foobar" exists in this element ) { index = i; } } document.write(index)

Answer 1

I'll preface by saying that this data structure is going to be tough to manage in general. I would suggest a scheme for where an operation is an object with well defined properties, rather than just an "array of stuff".

That said, you can use recursion to search the array.

• If any value in the array is another array, continue with the next level of recursion
• If any value is an object, search its values

const isPlainObject = require('is-plain-object');

const containsTerm = (value, term) => {
  // if value is an object, search its values
  if (isPlainObject(value)) {
    value = Object.values(value);
  }

  // if value is an array, search within it
  if (Array.isArray(value)) {
    return value.find((element) => {
      return containsTerm(element, term);
    });
  }

  // otherwise, value is a primitive, so check if it matches
  return value === term;
};

const index = object.operations.findIndex((operation) => {
  return containsTerm(operation, 'Go');
});