Pairing Up Two Lists (the zip operation)

This lesson covers pairing up two lists in Java, so you understand a way to handle multiple pieces of data together. It's for anyone searching "Java pairing two lists usage."

Combining two corresponding lists — like "a list of names" and "a list of scores" — into pairs, one at a time, is called a zip operation. Java has no dedicated method for this, so you combine them one at a time with a for loop.

The example uses a shared index, for (int i = 0; i < names.size(); i++), pairing up names.get(i) and scores.get(i) for display. Accessing both lists by the same index is the basic idea.

A common early mistake is not handling the case where the two lists have different lengths. Accounting for that case yourself is a very Java-like characteristic of this approach.

In real projects, this idea is applied often whenever you need to process several related lists together — a product name and its price, a label and its value, and more.

📖 Reference code

List<String> names = List.of("Alice", "Bob", "Charlie");
List<Integer> scores = List.of(88, 95, 72);

for (int i = 0; i < names.size(); i++) {
    System.out.println("(" + names.get(i) + ", " + scores.get(i) + ")");
}

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🧪 This site can't compile or run Java directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).