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JavaScript Object-Oriented JavaScript Working with Classes in JavaScript Adding methods to classes

Posted by Francisco Ortiz
Francisco Ortiz
2,673 Points

Why is this not returning the string?

Can anybody take a look at this and let me know what they are seeing that I am not?

adding_methods.js 
class Student {
 constructor(gpa){
  this.gpa = gpa;
 }
 stringGPA(){
  String(this.gpa)
 } 
}
const student = new Student(3.9);
console.log(student);
stringGPA();

2 Answers

Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 Points

I assume you meant to pass the value to "console.log". And since "stringGPA" is an instance method, it needs to be called on the class instance:

console.log(student.stringGPA());

Also, the method itself needs to have a "return" statement to pass back the value:

 stringGPA(){
  return String(this.gpa);  // add "return"
 }
Vitaly Khe
Vitaly Khe
7,160 Points
Vitaly Khe
Vitaly Khe
7,160 Points 
console.log(student.stringGPA())

will return undefined..

If you expected converting gpa to a string, you have to reassign this.gpa inside your stringGpa() method. Pls note - you call stringGPA() method on instance of Student class that you have created - student

class Student {
 constructor(gpa){
  this.gpa = gpa;
 }
 stringGPA(){
  this.gpa = String(this.gpa)
 }
}
const student = new Student(3.9);
student.stringGPA();

Finally, you can check the type of student.gpa property

console.log(typeof student.gpa);
qwe qwe
qwe qwe
208 Points
qwe qwe
qwe qwe
208 Points 
console.log("I'm Happy")