JS将未定义的值转换为空字符串

Question

我正在使用Object.assign()将值复制到对象:

const { one, two, three } = attributes;

return Object.assign( props, { 
  "data-one": one,
  "data-two": two,
  "data-three": three   
} );

如果属性的值为空,则返回undefined.我希望它返回一个空字符串或理想情况下不复制任何空属性.

我试过这个:

const { one, two, three } = attributes;

var oneValue = one ? one : "";
var twoValue = two ? two : "";
var threeValue = three ? three : "";

return Object.assign( props, { 
  "data-one": oneValue,
  "data-two": twoValue,
  "data-three": threeValue   
} );

它的工作原理是发送空值而不是未定义,但似乎不是很花哨.有没有更好的方法来处理这个？

Answer 1

您可以在使用解构时定义默认值.

const attributes = { one: 'one' };
const { one = '', two = '', three = '' } = attributes;
const props = {}

console.log(Object.assign( props, { 
  "data-one": one,
  "data-two": two,
  "data-three": three
}));

最后,如果您有许多常见的行为,您可以只命名要复制的属性并编写循环.