Tutorial :Android - Get value from HashMap



Question:

I have tried to search on HashMap in Android, but getting problem:

Consider this example:

HashMap<String, String> meMap=new HashMap<String, String>();  meMap.put("Color1","Red");  meMap.put("Color2","Blue");  meMap.put("Color3","Green");  meMap.put("Color4","White");  

now I want to iterate it and get the value of each color and want to display in "Toast". how do I display it?


Solution:1

Iterator myVeryOwnIterator = meMap.keySet().iterator();  while(myVeryOwnIterator.hasNext()) {      String key=(String)myVeryOwnIterator.next();      String value=(String)meMap.get(key);      Toast.makeText(ctx, "Key: "+key+" Value: "+value, Toast.LENGTH_LONG).show();  }  


Solution:2

Here's a simple example to demonstrate Map usage:

Map<String, String> map = new HashMap<String, String>();  map.put("Color1","Red");  map.put("Color2","Blue");  map.put("Color3","Green");  map.put("Color4","White");    System.out.println(map);  // {Color4=White, Color3=Green, Color1=Red, Color2=Blue}            System.out.println(map.get("Color2")); // Blue    System.out.println(map.keySet());  // [Color4, Color3, Color1, Color2]    for (Map.Entry<String,String> entry : map.entrySet()) {      System.out.printf("%s -> %s%n", entry.getKey(), entry.getValue());  }  // Color4 -> White  // Color3 -> Green  // Color1 -> Red  // Color2 -> Blue  

Note that the entries are iterated in arbitrary order. If you need a specific order, then you may consider e.g. LinkedHashMap

See also

Related questions

On iterating over entries:

On different Map characteristics:


On enum

You may want to consider using an enum and EnumMap instead of Map<String,String>.

See also

Related questions


Solution:3

This with no warnings!

    HashMap<String, String> meMap=new HashMap<String, String>();      meMap.put("Color1","Red");      meMap.put("Color2","Blue");      meMap.put("Color3","Green");      meMap.put("Color4","White");        for (Object o : meMap.keySet()) {          Toast.makeText(getBaseContext(), meMap.get(o.toString()),                  Toast.LENGTH_SHORT).show();      }  


Solution:4

HashMap<String, String> meMap = new HashMap<String, String>();  meMap.put("Color1", "Red");  meMap.put("Color2", "Blue");  meMap.put("Color3", "Green");  meMap.put("Color4", "White");    Iterator myVeryOwnIterator = meMap.values().iterator();  while(myVeryOwnIterator.hasNext()) {      Toast.makeText(getBaseContext(), myVeryOwnIterator.next(), Toast.LENGTH_SHORT).show();  }  


Solution:5

HashMap<String, String> meMap=new HashMap<String, String>();  meMap.put("Color1","Red");  meMap.put("Color2","Blue");  meMap.put("Color3","Green");  meMap.put("Color4","White");  Iterator iterator = meMap.keySet().iterator();  while( iterator. hasNext() ){      Toast.makeText(getBaseContext(), meMap.get(iterator.next().toString()),       Toast.LENGTH_SHORT).show();  }  


Solution:6

this work for me:

HashMap<String, String> meMap=new HashMap<String, String>();  meMap.put("Color1","Red");  meMap.put("Color2","Blue");  meMap.put("Color3","Green");  meMap.put("Color4","White");    Iterator iterator = meMap.keySet().iterator();  while( iterator. hasNext() )  {      Toast.makeText(getBaseContext(), meMap.get(iterator.next().toString()),       Toast.LENGTH_SHORT).show();  }  


Solution:7

If you know Key, use this code

String value=meMap.get(key);


Solution:8

for (Object key : meMap.keySet()) {          String value=(String)meMap.get(key);          Toast.makeText(ctx, "Key: "+key+" Value: "+value, Toast.LENGTH_LONG).show();      }  


Solution:9

 Iterator iterator = meMap.keySet().iterator();                  while(iterator.hasNext() ){                    //get key                      String key=(String)iterator.next();                      //toast value                                             Toast.makeText(getBaseContext(),""+(String)meMap.get(key),Toast.LENGTH_SHORT).show();                    }  

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