我正在为钢琴教师创建一种解决方案，以无纸化方式记录学生的所有作品。我遇到一个错误：每当我运行函数时，它都会返回未定义状态。这是我的代码：
MultipartRequest
错误：
class Student{
constructor(name){
this.name = name;
}
}
class StudentContainer{
constructor(studentArr){
this.students = studentArr;
}
}
StudentContainer.prototype.studentExists = function(nameToSearch){
for(var th in this.students){
if(this.students[th].name == nameToSearch){
return [true, parseInt(th)];
break;
}else if(parseInt(th)+1 == this.students.length){
return [false, -1];
}else{
}
}
}
StudentContainer.prototype.addStudent = function(studentToAdd){
this.students[this.students.length] = studentToAdd;
}
StudentContainer.prototype.addStudentConditional = function(studentToAdd){
var exists = this.studentExists(studentToAdd.name);
console.log(exists); //undefined
if(exists[0] == true){
return {"success": false, "index": exists[1]};
}else{
this.students[this.students.length] = studentToAdd;
return {"success": true, "index": this.students.length-1};
}
}
var y = new StudentContainer([]);
y.addStudentConditional(new Student("Sample"));
怎么了？有工作片段吗？