If I have a function:
function sliceArrayIntoGroups(arr, size) {
var slicedArray = arr.slice(0, size);
return slicedArray;
}
I am looking to take an array and slice it into an array of arrays.. how would I go about doing so?
So if I had this:
sliceArrayIntoGroups(["a", "b", "c", "d"], 2);
The result should be:
[["a","b"],["c","d"]]
But I don't know how to save the second part of the original array after slicing it.
Any help is appreciated.
The solution using regular while loop and custom step parameter:
function sliceArrayIntoGroups(arr, size) {
var step = 0, sliceArr = [], len = arr.length;
while (step < len) {
sliceArr.push(arr.slice(step, step += size));
}
return sliceArr;
}
console.log(sliceArrayIntoGroups(["a", "b", "c", "d"], 2));
console.log(sliceArrayIntoGroups(["a", "b", "c", "d", "e", "f"], 2));
console.log(sliceArrayIntoGroups(["a", "b", "c", "d", "e", "f"], 3));step option points to an offset of each extraction(slicing)
This ought to do it. It's a simple recursive function that slices n elements from the beginning of the array and calls itself with the remaining elements.
function sliceArrayIntoGroups(arr, size) {
if (arr.length === 0) { return arr; }
return [ arr.slice(0, size), ...sliceArrayIntoGroups(arr.slice(size), size) ];
}
console.log(sliceArrayIntoGroups([1,2,3,4,5], 2));
console.log(sliceArrayIntoGroups([1,2,3,4,5], 3));
console.log(sliceArrayIntoGroups([1,2,3,4,5], 10));
[["a","b","c","d"]]
try this, it will slice origin array to 2 pieces, then concat to 1 array
function sliceArrayIntoGroups(arr, size) {
if (size >= arr.length || size <= 0) { return arr; }
return [arr.slice(0, size), arr.slice(size)];
}
console.log(sliceArrayIntoGroups(["a", "b", "c", "d"], 2));Try this:
function sliceArrayIntoGroups(arr, size) {
var result = [];
while (arr.length > 0) {
result.push(arr.splice(0, size));
}
return result;
}
console.log(sliceArrayIntoGroups(["a", "b", "c", "d", "e", "f"], 3));
console.log(sliceArrayIntoGroups(["a", "b", "c", "d"], 2));function sliceArrayIntoGroups(arr, size) {
var result = [];
while (arr.length > 0) {
result.push(arr.splice(0, size));
}
return result;
}
This will divide array into pieces where each piece will be the size of size variable, so
sliceArrayIntoGroups(["a", "b", "c", "d", "e", "f"], 3);
will output
[["a", "b", "c"], ["d", "e", "f"]]
Javascript slice() method returns the selected elements in an array, as a new array object. So using for loop create smallArray and push them to arrGroup array.
function sliceArrayIntoGroups(arr, size) {
let arrGroup =[];
for (let i=0; i<arr.length; i+=size) {
let smallArray = arr.slice(i,i+size);//creating smaller array of required size using slice
arrGroup.push(smallArray);
}
return arrGroup;
}
Reduce:
var x = [1,2,3,4,5,6,7,8,9];
var chunk = function(arr,n) {
var temp;
return arr.reduce(function(carry,item,index) {
//if we're at a chunk point: index%n == 0
if(!(index%n)) {
//if temp currently holds items, push it onto carry
if(temp && temp.length) { carry.push(temp); }
//reset temp to an empty array
temp = [];
}
//push the current item onto temp
temp.push(item);
//if this is the last item in the array, push temp onto carry
index == arr.length-1 && carry.push(temp);
return carry;
},[]);
};
chunk(x,5);
