javascript - 我如何检查一个对象是否未定义(javascript)？

Question

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Answer 1

您必须在使用之前检查每个可能定义的属性:

function checkUnexistingObject(myUnexistingObject) {
  if (myUnexistingObject !== undefined) {
    if (myUnexistingObject.otherObject !== undefined) {
      console.log("All is well");
    }
  }
}
checkUnexistingObject({});
checkUnexistingObject({otherObject: "hey"});