将对象推入数组会两次输出相同的对象

Question

这是我写的函数：

fetchD = () => {
    fetch('http://localhost:3000/some route')
        .then((response) => {
            let jsonStr = response.json();

            jsonStr.then((result) => {
                //console.log(result);
                let localArrayOfFetchedData=[];
                let courseDetails = {
                    course_title: [],
                    course_description: [],
                    course_intro_video: [],
                    prerequisite_course_title: [],
                    created_on: [],
                    communication_language: [],
                    credit: [],
                    duration: [],
                };
                for (let i in result) {
                    courseDetails.course_title= result[i].course_title;  
                    courseDetails.course_description= result[i].course_description;  
                    courseDetails.course_intro_video= result[i].course_intro_video;  
                    courseDetails.prerequisite_course_title= result[i].prerequisite_course_title;  
                    courseDetails.created_on= result[i].created_on;  
                    courseDetails.communication_language= result[i].communication_language;  
                    courseDetails.credit= result[i].credit;  
                    courseDetails.duration= result[i].duration; 
                    console.log(courseDetails); 
                    this.CourseDatabase.push(courseDetails);             
                }
                console.log(this.CourseDatabase);                   
            })
        })
}

并且当我在控制台日志中时，数据iam被两次按下相同的对象（最后一个对象）：

Array (2)
0 {course_title: "ML", course_description: "Here you can learn basic about ML ",  …}
1 {course_title: "ML", course_description: "Here you can learn basic about ML ",  …}

但是我的数据库有两个不同的对象。我需要两个不同的对象。