A full guide to loops in Solidity

In this guide, we are going to learn how to create loops in Solidity and how they work. We're also going to learn how to use the break and continue keywords.

You have 2 ways to create a loop in Solidity, either with for or with while

Creating a for loop in Solidity

To create a for loop, it works pretty much like in JavaScript:

for (uint256 i = 0; i < 10; i++) {
    // do something here
}

And you can break the loop using the break keyword:

for (uint256 i = 0; i < 10; i++) {
    if (i == 2) {
        break;
    }
    // this loop will end when i == 2
}

Or you can skip an iteration with continue:

for (uint256 i = 0; i < 10; i++) {
    if (i == 2) {
        continue;
    }
    // this code will not be reached when i == 2 because of continue
}

Creating while loops

You can also use while to create loops. It's not recommended though because you can't always know when the condition will stop (if it's ever going to stop).

uint256 i = 0;
while (i < 10) {
    // do something here
    i++;
}

You can also make a do ... while loop:

uint256 i = 0;
do {
    // do something here
    i++;
} while (i < 10);

And that's it 🎉

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