filter with object references lodash

Question

I have an array, I need to chunk that array & manipulate parts of the chunks BUT I'd like to it to update my original array

I'm self taught with no computer science background so when it comes to technical inner workings I'm at a disadvantage.

 var markers = ["one","two","three","four","five","six","seven","eight","nine"] var chunks = _.chunk(markers, 5) var result = _.chain(chunks[0]).last().value(); result = 'newValue' console.log(chunks); console.log(markers); //was hopping to get // ["one","two","three","four","newValue","six","seven","eight","nine"] 

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Answer 1

I'm not quite sure I got your requirement right, but this changes the first and last element of each "chunk" (without really splitting the array).

 var data = [ "one","two","three","four","five", "one","two","three","four","five", "one","two","three" ]; var chunkSize = 5, numberOfChunks = Math.ceil(data.length / chunkSize), indexOfFirstElementInChunk, indexOfLastElementInChunk; for (var i = 0; i < numberOfChunks; i++) { indexOfFirstElementInChunk = (i * chunkSize); data[indexOfFirstElementInChunk] = "first element"; indexOfLastElementInChunk = Math.min(data.length, ((i + 1) * chunkSize)) - 1; if (indexOfFirstElementInChunk < indexOfLastElementInChunk) { data[indexOfLastElementInChunk] = "last element"; } } console.log(data);