Having trouble extracting a number from an array and encountering a "NaN" error

Question

Having trouble extracting a number from an array and encountering a "NaN" error

Encountering an issue with calculating the total grades in the class, as I am receiving an 'NAN' error. Attempted to use parseInt() and .value on students[i].grade but still facing difficulties because of my inexperience.

var students= [{name:"David", grade:80}, 
               {name:"Vinoth", grade:77}, 
               {name:"Divya", grade:88}, 
               {name:"Ishitha", grade:95},
               {name:"Thomas", grade:68}];


var average;

for(i = 0; i < students.length; i++){
    console.log(students[i].grade);
    average += Number(students[i].grade.value);
    console.log(average);
}

The output from console log appears as follows:

80 NaN 77 NaN 88 NaN 95 NaN 68 NaN

javascript

Answer 1

Answer №1

1) Ensure to set the initial value of average: var average = 0;

2) Avoid using .value as it is not a valid property.

average += Number(students[i].grade);

3) If all accessed properties are numbers, there is no need to unnecessarily convert number values into numbers using Number().

This code snippet accomplishes the task effectively:

var students= [{name:"David", grade:80}, 
           {name:"Vinoth", grade:77}, 
           {name:"Divya", grade:88}, 
           {name:"Ishitha", grade:95},
           {name:"Thomas", grade:68}];

var average = 0;

for(i = 0; i < students.length; i++){
    console.log(students[i].grade);
    average += Number(students[i].grade);
    console.log(average);
}

console.log("average: ", average/students.length);

Answer 2

1) Ensure to set the initial value of average: var average = 0;

2) Avoid using .value as it is not a valid property.

average += Number(students[i].grade);

3) If all accessed properties are numbers, there is no need to unnecessarily convert number values into numbers using Number().

This code snippet accomplishes the task effectively:

var students= [{name:"David", grade:80}, 
           {name:"Vinoth", grade:77}, 
           {name:"Divya", grade:88}, 
           {name:"Ishitha", grade:95},
           {name:"Thomas", grade:68}];

var average = 0;

for(i = 0; i < students.length; i++){
    console.log(students[i].grade);
    average += Number(students[i].grade);
    console.log(average);
}

console.log("average: ", average/students.length);

Having trouble extracting a number from an array and encountering a "NaN" error

Answer №1

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