getting a null response when using the map feature - coding battles

Question

getting a null response when using the map feature - coding battles

Given an array filled with integers, my goal is to generate a new array containing the averages of each integer and its following number. I attempted to achieve this using the map function.

var arr = [1,2,3,4];

arr.map(function(a, b){
   return (a + b / 2);
});

Although everything appears to work correctly when running this in the console, the problem arises when the challenge expects specific results. You can find the challenge here. Is there a simple mistake that I might be overlooking?

javascript arrays

Answer 1

Answer №1

If you utilize the callback parameters for Array#map, you will have access to the element itself, index, and reference to the array. Afterwards, assign the result to a variable and exclude the first element to ensure you have the necessary elements.

var arr = [1, 2, 3, 4],
    result = arr.map(function(a, i, aa) {
        return (aa[i - 1] + a) / 2;
    });

result.shift();
console.log(result);

Another approach would be using Array#reduce, which aligns better with your goal.

var arr = [1, 2, 3, 4],
    result = [];

arr.reduce(function(a, b) {
    result.push((a + b) / 2);
    return b;
});

console.log(result);

Answer 2

If you utilize the callback parameters for Array#map, you will have access to the element itself, index, and reference to the array. Afterwards, assign the result to a variable and exclude the first element to ensure you have the necessary elements.

var arr = [1, 2, 3, 4],
    result = arr.map(function(a, i, aa) {
        return (aa[i - 1] + a) / 2;
    });

result.shift();
console.log(result);

Another approach would be using Array#reduce, which aligns better with your goal.

var arr = [1, 2, 3, 4],
    result = [];

arr.reduce(function(a, b) {
    result.push((a + b) / 2);
    return b;
});

console.log(result);

Answer 3

Answer №2

One way to solve this problem is through iterating over the array.

calculateAverage = function(array){ 
  var result=[];
  for( var i=0; i<array.length-1; i++) {
    result.push((array[i]+array[i+1])/2)
  }
  return result;
}

Answer 4

One way to solve this problem is through iterating over the array.

calculateAverage = function(array){ 
  var result=[];
  for( var i=0; i<array.length-1; i++) {
    result.push((array[i]+array[i+1])/2)
  }
  return result;
}

Answer 5

Answer №3

It is important to have a solid grasp on map(), reduce(), and filter() in order to master JavaScript programming.

Answer 6

It is important to have a solid grasp on map(), reduce(), and filter() in order to master JavaScript programming.

getting a null response when using the map feature - coding battles

Answer №1

Answer №2

Answer №3

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