javascript - 未捕获的类型错误 : Cannot destructure property `name` of 'undefined' or 'null'

Question

在传递空对象的情况下，对象解构会引发错误

function test ({name= 'empty'}={}) {
  console.log(name)
}
test(null);

Uncaught TypeError: Cannot destructure property name of 'undefined' or 'null'. at test (:1:15) at :1:1

Answer 1

见docs :

Default function parameters allow named parameters to be initialized with default values if no value or undefined is passed.

换句话说，如果null，则不会分配默认参数。通过:

function fn(arg = 'foo') {
  console.log(arg);
}
fn(null);

改为在函数的第一行进行解构:

function test (arg) {
  const { name = 'empty' } = arg || {};
  console.log(name)
}
test(null);