Repeating work
Loops let you run the same block of code many times — once per item in a list, once per character in a string, or until a condition becomes false. They are how you process collections of data without writing the same line a hundred times.
/* CSS has no loops, but selectors apply to every matching element */
ul li {
padding: 0.5rem;
}for vs while
Use a for loop when you know up-front how many times to iterate or you are walking through a collection. Use while when you have to keep going until some condition is met — for example, reading lines from a file until the end is reached.
break and continue
break stops a loop immediately and continue skips to the next iteration. Use them to handle early exit conditions, but avoid burying them deep inside a complex loop — that makes flow hard to follow.