I got a quiz question in my Full Stack Web Development online course that states the following:
let sum = 0;
for (let i = 0; i < 5; i++) {
for (let j = 0; j < 2; j++) {
sum = sum + i + j;
continue;
}
}
console.log(sum);
Now, the correct answer to the question is 25 according to the answer of the quiz, but I have no idea how it gets to 25? The closest I get when writing it out on paper to try and visualize it, is either 15 / 16.
Could someone please write a visualization that would make it clearer for me on how this nested loop gets to 25?
Thanks in advance.
Add a console after second for, you should see the visualization
let sum = 0;
for (let i = 0; i < 5; i++) {
for (let j = 0; j < 2; j++) {
console.log(`sum=${sum} i=${i} j=${j}`)
sum = sum + i + j;
continue;
}
}
console.log(sum);
//output
// sum=0 i=0 j=0
// sum=0 i=0 j=1
// sum=1 i=1 j=0
// sum=2 i=1 j=1
// sum=4 i=2 j=0
// sum=6 i=2 j=1
// sum=9 i=3 j=0
// sum=12 i=3 j=1
// sum=16 i=4 j=0
// sum=20 i=4 j=1
// 25
Here are all the iterations of the loops, and the value of sum after each.
i = 0 j = 0 sum = 0 + 0 + 0 = 0
i = 0 j = 1 sum = 0 + 0 + 1 = 1
i = 1 j = 0 sum = 1 + 1 + 0 = 2
i = 1 j = 1 sum = 2 + 1 + 1 = 4
i = 2 j = 0 sum = 4 + 2 + 0 = 6
i = 2 j = 1 sum = 6 + 2 + 1 = 9
i = 3 j = 0 sum = 9 + 3 + 0 = 12
i = 3 j = 1 sum = 12 + 3 + 1 = 16
i = 4 j = 0 sum = 16 + 4 + 0 = 20
i = 4 j = 1 sum = 20 + 4 + 1 = 25
Perhaps this will give you more visualization of on what's going on:
let sum = 0;
for (let i = 0; i < 5; i++) {
console.log("loop start");
console.log("i", i);
for (let j = 0; j < 2; j++) {
console.log("sum", sum);
console.log("j", j);
sum = sum + i + j;
continue;
}
console.log("loop end");
}
console.log(sum);