Reputation: 5442
I am trying to use HashMap in Android sample project. Now, am doing sample project for learn android. I just store keys and values in HashMap, i want to show the keys and their values in EditView. I followed below code in my sample project. But, first key and value only printing in EditView.
Map<String, String> map = new HashMap<String,String>();
map.put("iOS", "100");
map.put("Android", "101");
map.put("Java", "102");
map.put(".Net", "103");
Set keys = map.keySet();
for (Iterator i = keys.iterator(); i.hasNext(); ) {
String key = (String) i.next();
String value = (String) map.get(key);
textview.setText(key + " = " + value);
}
In EditView iOS = 100
is only printing. I want to print all keys and their value in EditText. What am I doing wrong?
Upvotes: 74
Views: 254673
Reputation: 13657
To print all keys:
myMap.keys().toList().joinToString()
To print all entries:
myMap.map { "${it.key} :: ${it.value}" }.toList().joinToString()
Upvotes: 1
Reputation: 1416
With Java 8:
map.keySet().forEach(key -> System.out.println(key + "->" + map.get(key)));
Upvotes: 5
Reputation: 7856
Kotlin Answer
for ((key, value) in map.entries) {
// do something with `key`
// so something with `value`
}
You may find other solutions that include filterValues. Just keep in mind that retrieving a Key value using filterValues will include braces [].
val key = map.filterValues {it = position}.keys
Upvotes: -1
Reputation: 185
for (String entry : map.keySet()) {
String value = map.get(entry);
System.out.print(entry + "" + value + " ");
// do stuff
}
Upvotes: 4
Reputation: 776
For everyone who clicked on this to find out what the content of your HashMap is, the toString
method (docs) actually works with most objects. (note: a java array is not an object!)
So this woks perfectly fine for debugging purposes:
System.out.println(myMap.toString());
>>> {key1=value1, key2=value2}
Upvotes: -1
Reputation: 3572
First, there are errors in your code, ie. you are missing a semicolon and a closing parenthesis in the for loop.
Then, if you are trying to append values to the view, you should use textview.appendText(), instead of .setText().
There's a similar question here: how to change text in Android TextView
Upvotes: 12
Reputation: 229
You can do it easier with Gson:
Log.i(TAG, "SomeText: " + new Gson().toJson(yourMap));
The result will look like:
I/YOURTAG: SomeText: {"key1":"value1","key2":"value2"}
Upvotes: 14
Reputation: 102
public void dumpMe(Map m) { dumpMe(m, ""); }
private void dumpMe(Map m, String padding)
{
Set s = m.keySet();
java.util.Iterator ir = s.iterator();
while (ir.hasNext())
{
String key = (String) ir.next();
AttributeValue value = (AttributeValue)m.get(key);
if (value == null)
continue;
if (value.getM() != null)
{
System.out.println (padding + key + " = {");
dumpMe((Map)value, padding + " ");
System.out.println(padding + "}");
}
else if (value.getS() != null ||
value.getN() != null )
{
System.out.println(padding + key + " = " + value.toString());
}
else
{
System.out.println(padding + key + " = UNKNOWN OBJECT: " + value.toString());
// You could also throw an exception here
}
} // while
}
//This code worked for me.
Upvotes: 0
Reputation: 119
HashMap <Integer,Integer> hm = new HashMap<Integer,Integer>();
Set<Integer> keys = hm.keySet(); //get all keys
for(Integer i: keys)
{
System.out.println(hm.get(i));
}
Upvotes: 11
Reputation: 167
you can use this code:
for (Object variableName: mapName.keySet()){
variableKey += variableName + "\n";
variableValue += mapName.get(variableName) + "\n";
}
System.out.println(variableKey + variableValue);
this code will make sure that all the keys are stored in a variable and then printed!
Upvotes: 0
Reputation: 787
This code is tested and working.
public void dumpMe(Map m) { dumpMe(m, ""); }
private void dumpMe(Map m, String padding) {
Set s = m.keySet();
java.util.Iterator ir = s.iterator();
while (ir.hasNext()) {
String key = (String) ir.next();
Object value = m.get(key);
if (value == null) continue;
if (value instanceof Map) {
System.out.println (padding + key + " = {");
dumpMe((Map)value, padding + " ");
System.out.println(padding + "}");
}
else if (value instanceof String ||
value instanceof Integer ||
value instanceof Double ||
value instanceof Float ||
value instanceof Long ) {
System.out.println(padding + key + " = " + value.toString());
}
else {
System.out.println(padding + key + " = UNKNOWN OBJECT: " + value.toString());
// You could also throw an exception here
}
} // while
} // dumpme
Charles.
Upvotes: 1
Reputation: 641
It's because your TextView recieve new text on every iteration and previuos value thrown away. Concatenate strings by StringBuilder and set TextView value after loop. Also you can use this type of loop:
for (Map.Entry<String, String> e : map.entrySet()) {
//to get key
e.getKey();
//and to get value
e.getValue();
}
Upvotes: 12
Reputation: 29199
String text="";
for (Iterator i = keys.iterator(); i.hasNext()
{
String key = (String) i.next();
String value = (String) map.get(key);
text+=key + " = " + value;
}
textview.setText(text);
Upvotes: 2
Reputation: 6277
for (Map.Entry<String,String> entry : map.entrySet()) {
String key = entry.getKey();
String value = entry.getValue();
// do stuff
}
Upvotes: 191