如何循环和遍历包含objetcs和交换值的Javascript对象

Question

var person = {
          course1:{Name:"xxx", day:"mon", time:"2am-6pm"},
          course2:{Name:"yyy", day:"tue", time:"7am-9pm"},
          course3:{Name:"zzz", day:"tue", time:"2am-6pm"},
          course4:{Name:"aaa", day:"wed", time:"2am-6pm"},
          course5:{Name:"bbb", day:"thu", time:"2am-6pm"},
          course6:{Name:"ccc", day:"mon", time:"2am-6pm"} 
        };

Can anyone please show how to loop and iterate through this person object and swap the course1 and course2 object values(name, day, time) and do something, replace it and swap course1 and course3 again do something and so on...

Answer 1

You can use Object.keys in order to get all an array of keys, and then you can iterate over it.

Something like that:

 const person = { course1: { Name: "xxx", day: "mon", time: "2am-6pm" }, course2: { Name: "yyy", day: "tue", time: "7am-9pm" }, course3: { Name: "zzz", day: "tue", time: "2am-6pm" }, course4: { Name: "aaa", day: "wed", time: "2am-6pm" }, course5: { Name: "bbb", day: "thu", time: "2am-6pm" }, course6: { Name: "ccc", day: "mon", time: "2am-6pm" } }; Object.keys(person).forEach((key) => { const course = person[key]; // Do your logic here... }); 

Answer 2

const person = {
    course1:{Name:"xxx", day:"mon", time:"2am-6pm"},
    course2:{Name:"yyy", day:"tue", time:"7am-9pm"},
    course3:{Name:"zzz", day:"tue", time:"2am-6pm"},
    course4:{Name:"aaa", day:"wed", time:"2am-6pm"},
    course5:{Name:"bbb", day:"thu", time:"2am-6pm"},
    course6:{Name:"ccc", day:"mon", time:"2am-6pm"} 
};

const courses = Object.keys(person).filter(course => course !== 'course1');

courses.forEach(key => {
    const copyOne = Object.assign({}, person['course1']);
    const copyCurrent = Object.assign({}, person[key]);

    person['course1'] = copyCurrent;
    person[key] = copyOne;
});

console.log(person);

You want to compare with course1 on each iteration, so it doesn't make sense to use the key in forEach .

Answer 3

// find the least expensive course

// for easier coding, set a cost property for each course.
for(let course in person) {
    course['cost'] = getCourseCost(course);
}

let lowestCostCourse = person['course1'];

// this compares person['course1'] to itself, but so what
for(let course in person) {
    if(course['cost'] < lowestCostCourse['cost']) {
       lowestCostCourse = course;
    }
}