Strings as key in Hashmap

Question

I'm newbie with Java Is it possible to convert a String, or a String[] as the keys of an Hashmap? I mean:

String keysToConvert = "key1,key2,key3";

into

HashMap<String, Double> hashmap = new HashMap<String, Double>();
[apply in some way the keys of the string]
hashmap.get("key2");

I know that hashmap.get("key2");has no value in this moment. I just would know if there is a way to load the keys in an HashMap.

If you have String[], you can add them using a for-each loop. — peterremec, Jun 06 '16 at 11:40
Yes, there is a way. Try to read about `String#split` method. — Pshemo, Jun 06 '16 at 11:41
your need is not clear what do you mean by " I just would know if there is a way to load the keys in an HashMap" what exactly is not clear to you? — Nicolas Filotto, Jun 06 '16 at 11:43

score 3 · Answer 1 · edited Jun 06 '16 at 11:43

3

hashmap.put("key2", 1.0d);
System.out.println(hashmap.get("key2")); // prints 1.0

This is the basic usage of a Map

edited Jun 06 '16 at 11:43

Pshemo

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answered Jun 06 '16 at 11:41

michael_bitard

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peterremec · Accepted Answer · 2016-06-06T11:49:10.990

1

If you have String[], you can add them using a for-each loop:

String[] keys = {"key1", "key2", "key3"};
HashMap<String, Double> hashmap = new HashMap<String, Double>();

for (String key : keys) {
    hashmap.put(key, null);
}

edited Jun 06 '16 at 11:49

answered Jun 06 '16 at 11:44

peterremec

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Strings as key in Hashmap

2 Answers2