javascript - 如何从过滤器的过滤器返回值？

Question

我想让所有以数学为主题的学生

var student = [{
  name: 'XYZ',
  age: 15,
  subject: ['Maths', 'Science'],
}, {
  name: 'XYZ',
  age: 15,
  subject: ['Hindi', 'Science'],
}, {
  name: 'XYZ',
  age: 15,
  subject: ['Maths', 'English'],
}];

我已经试过了但是没有用:

student.filter(x=>x.subject.filter(y=>y=='Maths'));

任何帮助将不胜感激

Answer 1

需要结合filter()宽度some()来判断是否有科目Maths

var student = [{
    name: 'XYZ',
    age: 15,
    subject: ['Maths', 'Science'],
  },
  {
    name: 'XYZ',
    age: 15,
    subject: ['Hindi', 'Science'],
  },
  {
    name: 'XYZ',
    age: 15,
    subject: ['Maths', 'English'],
  }
];

console.log(student.filter(x => x.subject.some(y => y == 'Maths')));