I have an array with multiple arrays inside. I would like to multiply the contents of each array.
Here is my code--currently not getting anything in console. The desired output is 3 numbers-- the result of multiplication of the three arrays
var arr = [
[1, 2, 3],
[3, 4],
[7, 8, 9]
]
var mult = 1
for (i = 0; i < arr.length; i++) {
for (j = 0; j < arr.length; j++) {
mult *= arr[i][j]
}
console.log(mult)
}You could map the result of the nested multiplying.
const
multiply = (a, b) => a * b,
array = [[1, 2, 3], [3, 4], [7, 8, 9]],
result = array.map(a => a.reduce(multiply, 1));
console.log(result);You should iterate over rows. So you need to change inner loop on this :
for (j = 0; j < arr[i].length; j++)
const array = [
[1, 2, 3],
[3, 4],
[7, 8, 9]
];
for (i = 0; i < array.length; i++) {
let result = 1;
for (j = 0; j < array[i].length; j++) {
result *= array[i][j]
}
console.log(result);
}You can try this, it is easier using map and reduce functions. arr.map(array => array.reduce(arrayMult, 1)) is the multiplication of each inner array, like [ 6, 12, 504 ], and the last reduce is to multiply these values.
var arr = [[1, 2, 3],[3, 4],[7, 8, 9]];
const arrayMult = (prev, curr) => prev * curr;
const total = arr.map(array => array.reduce(arrayMult, 1)).reduce(arrayMult, 1);