Need help for javascript code

[Malkazi]

I want a help about my code because i can't have an output and I don't know where's the error

let arr = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
console.log(arr);
for(let i = arr.length; i >= 0; i--){
console.log(arr);
for(let j = arr.length; j >= 0; j--){
console.log(arr[j]);
}
}

 

[pdiddles03]

in your second for loop, it should be:

for(let j  = arr[i].length; j>=0; j--){
    console.log(arr[i][j]);
}

Instead of:

for(let j  = arr.length; j>=0; j--){
    console.log(arr[j]);
}

 

[Malkazi]

in your second for loop, it should be:

for(let j  = arr[i].length; j>=0; j--){
    console.log(arr[i][j]);
}

Instead of:

for(let j  = arr.length; j>=0; j--){
    console.log(arr[j]);
}

Yeah but when i rectify my code as you said
I have the code below

let arr = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
console.log(arr);
for(let i = arr.length; i >= 0; i--){
console.log(arr[i]);
for(let j = arr[i].length; j >= 0; j--){
console.log(arr[i][j]);
}
}

But I still have error

 

[pdiddles03]

Try this:

let arr = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
for(let i = arr.length; i > 0; i--){
    console.log(arr[i-1])
    for(let j =  arr[i-1].length; j > 0; j--){
        console.log(arr[i-1][j-1])
    }
}