Display an array comprising of other arrays

Question

Display an array comprising of other arrays

function PersonXYZ(fName, lName) {
this.lastName = lName;
this.firstName = fName;
this.grades = [];

this.grades.push([4, 67, 5]);
this.grades.push([41, 63, 5]);
this.grades.push([4, 67, 55]);
} 

var person = new PersonXYZ('John', 'Doe');


person.grades.forEach(function iterateArray(arr1, arr2) {
  arr1.forEach(function displayValue(val1) {
    console.log(val1);
  });
  arr2.forEach(function displayValue(val2) {
     console.log(val2);
  });
});

I encountered the Error: arrSch2.forEach is not a function

I am puzzled as to why arrSch2.forEach is not working properly. Isn't the second element of grades an array with the values [41, 63, 5]?

javascript arrays printing foreach

Answer 1

Answer №1

When it comes to the forEach function, the second parameter is the index. In this case, arrSch2 is simply a number and the forEach method does not apply to numbers.

Looking at it from a different angle:

peprson.marks.forEach(function callBack(arrSch1, index) {
    ...
}

Answer 2

When it comes to the forEach function, the second parameter is the index. In this case, arrSch2 is simply a number and the forEach method does not apply to numbers.

Looking at it from a different angle:

peprson.marks.forEach(function callBack(arrSch1, index) {
    ...
}

Answer 3

Answer №2

The third value of the array is [13, 79, 8], however, this is not what is being passed in your parameters. If you simply wish to loop through the array, you can use code similar to the example below:

function PersonXYZ(fn, ln) {
  this.lastname = ln;
  this.firstname = fn;
  this.scores = [];

  this.scores.push([6, 81, 2]);
  this.scores.push([13, 79, 8]);
  this.scores.push([6, 81, 22]);
}

var individual = new PersonXYZ('Joe', 'Smith');

individual.scores.forEach(function (array) {
  array.forEach(function (num) {
    console.log(num);
  });
});

Answer 4

The third value of the array is [13, 79, 8], however, this is not what is being passed in your parameters. If you simply wish to loop through the array, you can use code similar to the example below:

function PersonXYZ(fn, ln) {
  this.lastname = ln;
  this.firstname = fn;
  this.scores = [];

  this.scores.push([6, 81, 2]);
  this.scores.push([13, 79, 8]);
  this.scores.push([6, 81, 22]);
}

var individual = new PersonXYZ('Joe', 'Smith');

individual.scores.forEach(function (array) {
  array.forEach(function (num) {
    console.log(num);
  });
});

Answer 5

Answer №3

When using Array.prototype.forEach, the callback function requires three arguments:

currentValue - Represents the current element being processed in the array.
index - Indicates the index of the current element being processed in the array.
array - Refers to the array to which forEach() is applied.

Note that arrSch2 is a number, not an array.

Below is the revised code that eliminates the second forEach call:

function PersonAMK(vn, ln) {
this.nachname = ln;
this.vn = vn;
this.marks = [];

this.marks.push([4, 67, 5]);
this.marks.push([41, 63, 5]);
this.marks.push([4, 67, 55]);
} 

var peprson = new PersonAMK('Unknwon', 'Unknown');


peprson.marks.forEach(function callBack(arrSch1) {
  arrSch1.forEach(function callBack(nod1) {
    console.log(nod1);
  });
});

Answer 6

When using Array.prototype.forEach, the callback function requires three arguments:

currentValue - Represents the current element being processed in the array.
index - Indicates the index of the current element being processed in the array.
array - Refers to the array to which forEach() is applied.

Note that arrSch2 is a number, not an array.

Below is the revised code that eliminates the second forEach call:

function PersonAMK(vn, ln) {
this.nachname = ln;
this.vn = vn;
this.marks = [];

this.marks.push([4, 67, 5]);
this.marks.push([41, 63, 5]);
this.marks.push([4, 67, 55]);
} 

var peprson = new PersonAMK('Unknwon', 'Unknown');


peprson.marks.forEach(function callBack(arrSch1) {
  arrSch1.forEach(function callBack(nod1) {
    console.log(nod1);
  });
});

Answer 7

Answer №4

Have you thought about employing a basic for loop for this task?

function PersonAMK(vn, ln) {
this.nachname = ln;
this.vn = vn;
this.marks = [];

this.marks.push([4, 67, 5]);
this.marks.push([41, 63, 5]);
this.marks.push([4, 67, 55]);
} 

var peprson = new PersonAMK('Unknwon', 'Unknown');

   for (i = 0; i < peprson.marks.length; i++) { 
      for (j = 0; j < peprson.marks[i].length; j++){ 
          console.log(peprson.marks[i][j]);    
      }
   }

Give this a try. Use the JSON.stringify() method to get the following output:

{"nachname":"Unknown","vn":"Unknwon","marks":[[4,67,5],[41,63,5],[4,67,55]]}

. Remember to iterate over peprson.marks as it contains arrays at each index. Best of luck!

Answer 8

Have you thought about employing a basic for loop for this task?

function PersonAMK(vn, ln) {
this.nachname = ln;
this.vn = vn;
this.marks = [];

this.marks.push([4, 67, 5]);
this.marks.push([41, 63, 5]);
this.marks.push([4, 67, 55]);
} 

var peprson = new PersonAMK('Unknwon', 'Unknown');

   for (i = 0; i < peprson.marks.length; i++) { 
      for (j = 0; j < peprson.marks[i].length; j++){ 
          console.log(peprson.marks[i][j]);    
      }
   }

Give this a try. Use the JSON.stringify() method to get the following output:

{"nachname":"Unknown","vn":"Unknwon","marks":[[4,67,5],[41,63,5],[4,67,55]]}

. Remember to iterate over peprson.marks as it contains arrays at each index. Best of luck!

Display an array comprising of other arrays

Answer №1

Answer №2

Answer №3

Answer №4

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