Data structures - the "this" keyword

Question

1.00/5 (1 vote)

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Hello Everyone,

I am solving some assignment but I don't understand how to solve this task.

let classroom = {
    numOfStudents: 0,
    schoolHours: false,
    playtime: false,
    openSchool: function() {
        this.schoolHours = true;
        this.numOfStudents = 20;

*Inside the breakTime function, and using the this keyword where necessary, check if the key schoolHours is true, and if it is, set the key playtime to true

What I have tried:

let classroom = {
    numOfStudents: 0,
    schoolHours: false,
    playtime: false,
    openSchool: function() {
        this.schoolHours = true;
        this.numOfStudents = 20;
    },
    breakTime: function() {
       
           
     this.playTime= true;   
       
    }
};


classroom.openSchool(); 
console.log(classroom.numOfStudents);
classroom.breakTime();
console.log(classroom.playTime);

Posted 24-Apr-23 5:30am

adla099

Updated 14-May-23 11:24am

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3 solutions

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Richard MacCutchan · Accepted Answer · 2023-04-24T05:36:00

Solution 1

Quote:
check if the key schoolHours is true

Which means you need an if test.

Posted 24-Apr-23 5:36am

Richard MacCutchan

Comments

adla099 24-Apr-23 11:40am

Thanks for your answer. Please what goes inside the if () {

Richard MacCutchan 24-Apr-23 11:57am

The question tells you.

adla099 24-Apr-23 12:04pm

I have tried everything. 'Does the function breakTime work correctly? did you use the this key word correctly in the appropriate places?'

Richard MacCutchan 24-Apr-23 12:07pm

I have tried everything.
Well, obviously not, since you have not added the if statement to the function. I suggest you take as look at JavaScript if else else if[^].

adla099 24-Apr-23 12:51pm

let classroom = {
numOfStudents: 0,
schoolHours: false,
playtime: false,
openSchool: function() {
this.schoolHours = true;
this.numOfStudents = 20;

breakTime: function(){
if(){
playtime=true;

Nothing placed in the if works. Could you please provide me the solution. got undefined

Richard MacCutchan 25-Apr-23 3:14am

Go to rthe link I gave you in my previous mesdsage, it gives a clear example.

adla099 25-Apr-23 17:16pm

when i use the if statement i get undefined

Richard MacCutchan 26-Apr-23 3:22am

Please show the actual code you are using, and the full text of the error message(s). We cannot guess what you are doing.

adla099 26-Apr-23 6:44am

Hi,
the first i get undefined. second logs true but i get this error (⚠ Hint
Does the function breakTime work correctly? did you use the this key word correctly in the appropriate places?)

breakTime: function() {

for (let schoolHours in classroom) {
if (classroom[schoolHours] == true) {

return true;
}
this.playtime=true;
}

}

breakTime: function() {

if (classroom.schoolHours===true) {
this.playtime=true;

}

Richard MacCutchan 26-Apr-23 7:05am

That is just random lines of code without any logic. What is the for statement supposed to do? Why do you have a return statement when the assignment specifically tells you to set the value of playtime?

Think about this in simple terms:

IF the value of schoolHours is TRUE
THEN
    SET the value of playTime to TRUE
END IF

adla099 26-Apr-23 7:14am

this logs true to the console but i still get the (⚠ Hint
Does the function breakTime work correctly? did you use the this key word correctly in the appropriate places?)

breakTime: function() {

if (classroom.schoolHours===true) {
this.playtime=true;

}
}

Richard MacCutchan 26-Apr-23 7:21am

I do not know what you mean by, " i still get the (⚠ Hint".

adla099 26-Apr-23 8:49am

I am working with a school LMS. So when the answer is not correct I get a hint about what went wrong

adla099 26-Apr-23 9:32am

Thanks alot. it worked. I used if statement but you are supposed to put function(schoolHours) and if(this.schoolHours===true) as OriginalGriff suggested in his solution.

inside the if statement you set playtime key;
this.playtime= true;

Richard MacCutchan 26-Apr-23 9:43am

Which is exactly what I have been trying to get you to understand.

OriginalGriff · Accepted Answer · 2023-04-24T06:43:00

To add to what Richard has said, this always refers to the current instance of the class it is used in: it allows you to be specific as with which of several variables of the same name you intended to use. For example if you have a method with a parameter called foo and a class level variable also called foo, then inside the method the parameter takes precedence and you need this.foo to access the class level variable.

See here: JavaScript this[^]

Member 16004134 · Accepted Answer · 2023-05-14T11:24:00

Solution 4

JavaScript

breakTime:function(){
        if(this.schoolHours){
            this.playtime = true;
        }
    }

Posted 14-May-23 11:24am

Member 16004134