How do nested for loops work?

Answer 1

Which language?

One example would be a two-dimensional array, which is filled with data.
The first loop goes through the first index and the second loop goes through the second index.

Something like this:

FOR (START; END; INCREMENT)
FOR (START; END; INCREMENT)
... some code ...
END FOR
END FOR

Here is an example to fill a two-dimensional array with numbers in Javascript:

for (let i=0; i<8; i++) {
for (let j=0; j<8; j++) {
arr[i][j] = i + "-" + j;
}
}

Answer 2

Basically like numbers.

Try this (example in Python):

for i in range(10):
for j in range(10):
print(str(i)+str(j))

Answer 3

I prefer the example with js or c++

Answer 4

https://code.sololearn.com/Wi4j8DVOINxE/?ref=app

Answer 5

To illustrate:
while(true){
while(true){
while(true){
std::cout<<"hi";
}}}

is the same as:
while(true){
std::cout<<"hi";
}

this can be observed if you step through every line of code using an IDE such as Visual Studio.

Answer 6

In c++:
for(int i=0;i<9;i++){
for(int i=0;i<9;i++)std::cout<<i;
}

This prints: "0123456789" 10 times.
The innermost loop executes before the outer executes.