如何同时检查对象和其他字段中的数组是否为空？

Question

假设我有这样的对象：

filter: {
masterName: '',
service:[],
}

如何检查数组和 masterName 字段是否为空？

Answer 1

只要对他们每个的length属性进行求值，看长度是否为0，如下例所示：

var filter = {
  masterName: '',
  service: [],
}

// Checks whether masterName is zero-length
if (filter.masterName.length === 0) {
  console.log('masterName is empty');
}

// Checks whether service is zero-length
if (filter.service.length === 0) {
  console.log('service is empty');
}

// Checks whether either are zero-length
if (filter.masterName.length === 0 && filter.service.length === 0) {
  console.log('Both are empty');
}

字符串长度被描述为 here 为：

The length property of a String object contains the length of the string, in UTF-16 code units

数组长度描述为 here 为：

The length property of an object which is an instance of type Array sets or returns the number of elements in that array.

如何同时检查对象和其他字段中的数组是否为空？

How to check If array is empty in Object and the other fields at the same time?

javascript

arrays

iteration

object