I'm trying to put certain value in certain two dimensional array but it appends different.
Here is my code.
const arr = []
const tdArr = []
arr.length = 5
arr.fill('p', 0)
for(let i = 0; i < arr.length; i++){
tdArr.push(arr)
}
const makeRnd = (min, max) => {
min = Math.ceil(min)
max = Math.floor(max)
return Math.floor(Math.random() * (max - min)) + min
}
let firstRnd = makeRnd(0, 4)
let secRnd = makeRnd(0, 4)
let tdArr2 = [...tdArr]
tdArr2[firstRnd][secRnd] = 'q'
console.log(tdArr2)I don't know why not (for example) tdArr2[0][1] is not changed but also change all second value of arrays.
It seems easy one but cannot google it :( Thanks for help!
Use tdArr.push([...arr]) in the for loop instead of tdArr.push(arr).
const arr = []
const tdArr = []
arr.length = 5
arr.fill('p', 0)
for(let i = 0; i < arr.length; i++){
tdArr.push([...arr])
}
const makeRnd = (min, max) => {
min = Math.ceil(min)
max = Math.floor(max)
return Math.floor(Math.random() * (max - min)) + min
}
let firstRnd = makeRnd(0, 4)
let secRnd = makeRnd(0, 4)
let tdArr2 = [...tdArr]
tdArr2[firstRnd][secRnd] = 'q'
console.log(tdArr2)As mentioned by @Dave Newton every element of tdArr array is the same one which is a reference to arr so when you change a value of arr all elements of tdArr are changes as they all reference the same array.
I would push an array literal instead of creating an array and then push it or create a copy like mentioned in the answer above and push the copy on each iteration.
tdArr.push(['p']);