How can I initialize an array with 5 zero elements in JavaScript without using the classic var arr = [0, 0, 0, 0, 0] method?
I've tried a few variations:
var arr = new Array(5).map(() => 0);
var arr = new Array(5).map(function () {return 0;});
var arr = Array(5).map(function () {return 0;});
Unfortunately, these examples are not working. Any ideas?
To achieve this, you have two options:
const array = new Array(5).fill(0);
console.log(array);Alternatively, you can use Array.from with a custom mapping function:
const array = Array.from({ length: 5 }, () => 0);
console.log(array);For more information, refer to the MDN documentation:
The map function iterates through elements in an array, applies a callback function, and generates a new array based on the returned values. It only runs the callback on elements with assigned values, including undefined. Elements that are missing, deleted, or never assigned a value are not processed.
When using Array.from, undefined values are assigned to array elements. This differs from using new Array, which does not assign undefined values, making it possible to apply map after using Array.from but not after using the Array constructor directly.
In order to initialize arrays, it is necessary to employ the fill method.
For instance:
const numbers = new Array(3).fill(0);
Could a for loop be the solution you're looking for?
for(i=0; i<N; i++){
array[i]=value;
}
If we have a 5-element array filled with zeros, it would look like this
for(i=0; i<5; i++){
array[i]=0;
}
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