Sending an argument to a prototype function

Question

I am trying to understand how to use a prototype with an array of objects in JavaScript. I am trying to send an argument to each Person object by using a subscript because I was thinking of using a loop with an index. With the current code I keep getting an error message that needsGlasses is not a function.

//class constructor
function Person (name, age, eyecolor) {
this.name = name;
this.age = age;
this.eyecolor = eyecolor;
}

//array of Person objects
var peopleArray = 
[
new Person ("Abel", 16, blue),
new Person ("Barry", 17, brown),
new Person "Caine", 18, green),
];

//prototype
Person.prototype.needsGlasses=function(boolAnswer){
    if (boolAnswer ==1){
        console.log("Needs glasses.");
       }
    if (boolAnswer !=1){
        console.log("Does not need glasses.");
       }
 }

//when I try to send a '1' or '0' to an object in the array, I get an error.
peopleArray[0].needsGlasses(1);

Answer 1

You have syntax errors. To get your code working it may be defined as follows:

function Person (name, age, eyecolor) {
  this.name = name;
  this.age = age;
  this.eyecolor = eyecolor;
}
Person.prototype.needsGlasses= function(boolAnswer){
    if (boolAnswer ==1){
        console.log("Needs glasses.");
    } else { 
        console.log("Does not need glasses.");
    }
}

var peopleArray = 
[
  new Person ("Abel", 16, "#00f"),
  new Person ("Barry", 17, "#A52A2A"),
  new Person ("Caine", 18, "#f00"),
];

peopleArray[0].needsGlasses(1);

Furthermore, you have unnecessary if statements.

You can try to play with this code on JSBin

Answer 2

It works but you code was full of sytax errors.

 function Person (name, age, eyecolor) { this.name = name; this.age = age; this.eyecolor = eyecolor; } //array of Person objects var peopleArray = [ new Person ("Abel", 16, 'blue'), new Person ("Barry", 17, 'brown'), new Person ("Caine", 18, 'green') ]; //prototype Person.prototype.needsGlasses = function (boolAnswer) { if (boolAnswer ==1) { console.log("Needs glasses."); } else { console.log("Does not need glasses."); } } //when I try to send a '1' or '0' to an object in the array, I get an error. peopleArray[0].needsGlasses(1);