CODEWITHSUNDEEP
javascriptecmascript-6
Jernst Jackson
Jernst Jackson

Reputation: 13

It keeps returning NaN(Not a Number) in my console

here's the object with arrays:

const studentGrades = [
    [{ studentID: 1, Q1: 89.3, Q2: 91.2, Q3: 93.3, Q4: 89.8 }],
    [{ studentID: 2, Q1: 69.2, Q2: 71.3, Q3: 76.5, Q4: 81.9 }],
    [{ studentID: 3, Q1: 95.7, Q2: 91.4, Q3: 90.7, Q4: 85.6 }],
    [{ studentID: 4, Q1: 86.9, Q2: 74.5, Q3: 83.3, Q4: 86.1 }],
    [{ studentID: 5, Q1: 70.9, Q2: 73.8, Q3: 80.2, Q4: 81.8 }]
];

I tried doing the following, it must have 1 decimal point and must be a number:

studentGrades.forEach( function(grade){
    
    grade.average = grade.Q1 + grade.Q2 + grade.Q3 + grade.Q4/4
    parseFloat(grade.average).toFixed(1);
    
});

But it keeps returning NaN in my console.

Upvotes: 1

Views: 44

Answers (3)

Marci
Marci

Reputation: 314

You must add [0] to grade because your studentGrades is a array of arrays.

studentGrades.forEach( function(grade){
        grade.average = (grade[0].Q1 + grade[0].Q2 + grade[0].Q3 + grade[0].Q4) / 4;
        parseFloat(grade.average).toFixed(1);
    });

Upvotes: 1

Rajdeep D
Rajdeep D

Reputation: 3910

Your data is Array inside an array, hence you need to add grade[0]

const studentGrades = [
    [{ studentID: 1, Q1: 89.3, Q2: 91.2, Q3: 93.3, Q4: 89.8 }],
    [{ studentID: 2, Q1: 69.2, Q2: 71.3, Q3: 76.5, Q4: 81.9 }],
    [{ studentID: 3, Q1: 95.7, Q2: 91.4, Q3: 90.7, Q4: 85.6 }],
    [{ studentID: 4, Q1: 86.9, Q2: 74.5, Q3: 83.3, Q4: 86.1 }],
    [{ studentID: 5, Q1: 70.9, Q2: 73.8, Q3: 80.2, Q4: 81.8 }]
];

studentGrades.forEach( function(grade){
    
    grade[0].average = (grade[0].Q1 + grade[0].Q2 + grade[0].Q3 + grade[0].Q4)/4;
    parseFloat(grade[0].average).toFixed(1);
    
});

console.log(studentGrades);

Upvotes: 1

Dani
Dani

Reputation: 895

studentGrades is an array of arrays, you should remove the brackets outside the actual studentGrade if they are not necessary and make it like this :

const studentGrades = [
{ studentID: 1, Q1: 89.3, Q2: 91.2, Q3: 93.3, Q4: 89.8 },
{ studentID: 2, Q1: 69.2, Q2: 71.3, Q3: 76.5, Q4: 81.9 },
{ studentID: 3, Q1: 95.7, Q2: 91.4, Q3: 90.7, Q4: 85.6 },
{ studentID: 4, Q1: 86.9, Q2: 74.5, Q3: 83.3, Q4: 86.1 },
{ studentID: 5, Q1: 70.9, Q2: 73.8, Q3: 80.2, Q4: 81.8 }
];

Upvotes: 1

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