New Array(_).fill(object) Does Not Create New Instances Of Object

ES6 allows us to fill an Array with a certain value: function emptyRow() { return new Array(9).fill(0); } This function returns an Array of length 9, filled with only zeros: &

Solution 1:

Array#fill won't help you, it accepts the value returned by emptyRow(), the already created object. You could use Array#map which accepts a function, although you won't be able to use the new Array() constructor. Here's the simplest way:

functionemptyMatrix() {
  Array.apply(null, {length: 9}).map(emptyRow);
  // create the array            fill in values
}

Or, more generally:

functiongenerateArray(n, valueFactory) {
  returnArray.apply(null, {length: n}).map(valueFactory);
}

Solution 2:

An other solution with map():

var line = newArray(9).fill(0);
var matrix = line.map(x =>newArray(9).fill(0))
console.log(matrix);

Solution 3:

You can use Array.from() to generate an array of specific length, and then Array.prototype.map() to fill it with empty rows:

constemptyRow = () => Array(9).fill(0);

constgenerateArray = (n, valueFactory) => Array.from({length: 9}).map(valueFactory);

console.log(generateArray(9, emptyRow));

Solution 4:

You can use Array.from() to create arrays of any length you want, and initialize them:

constcreateMatrix = (x, y) => Array.from({ length: x }, () =>Array.from({ length: y }, () =>0)
);

const result = createMatrix(9, 5);

console.log(result);

Solution 5:

functionemptyMatrix(length) {
  var matrix = newArray();
  for (var i = 0; i < length; i++)
    matrix[i] = newArray(length).fill(0)
  return matrix

}
console.log(emptyMatrix(5))

You can set length of your matrix