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27 lines
783 B
27 lines
783 B
5 years ago
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This issue is raised when
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- iterating over a HashMap with `ketSet()` iterator
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- looking up the key each time
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Instead, it is more efficient to iterate over the loop with `entrySet` which returns key-vaue pairs and gets rid of the hashMap lookup.
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For instance, we would raise an issue for the following program:
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```java
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void inefficient_loop_bad(HashMap<String, Integer> testMap) {
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for (String key : testMap.keySet()) {
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Integer value = testMap.get(key); // extra look-up cost
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foo(key, value);
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}
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}
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```
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Instead, it is more efficient to have:
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```java
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void efficient_loop_ok(HashMap<String, Integer> testMap) {
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for (Map.Entry<String, Integer> entry : testMap.entrySet()) {
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String key = entry.getKey();
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Integer value = entry.getValue();
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foo(key, value);
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}
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}
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```
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