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Switch Statement Java basic example


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Switch statement with numbers and array of strings Java example.


public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = { "One", "Two", "Three", "Four" };

		int i = 2;
		switch (i) {
			case 1: {
				System.out.println(arrayOfString[i]);
				break;
			}
			case 2: {
				System.out.println(arrayOfString[i]);
				break;
			}
			case 3: {
				System.out.println(arrayOfString[i]);
				break;
			}
			default: {
				System.out.println("Enter a valid value.");
			}
		} // END of switch
	}
}
/*
 * Three
 */




Possible:

case 1:
 System.out.println(arrayOfString[i]);
break;

// i love this notation 
case 1:{
 System.out.println(arrayOfString[i]);
}break;

case 1:{
 System.out.println(arrayOfString[i]);
 break;
}


397LW NO topic_id




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Další témata ....(Topics)


102

Unable to resolve id for attribute id Graphical layout editor Eclipse error | unable-to-resolve-id-for-attribute-id-graphical-layout-editor-eclipse-error


Problem: erroneous entry of id

<RadioButton android:id="idRadio"
                android:text="My radio button"/>


Solution: @+id/

<RadioButton android:id="@+id/idRadio"
                android:text="My radio button"/>
96

onSaveInstanceState() onRestoreInstanceState() basic Android example | onsaveinstancestate-onrestoreinstancestate-basic-android-example



public class MyClass extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       }
	 String sMyText = "some text";
	 int nMyInt = 10;

 @Override
 protected void onSaveInstanceState(Bundle outState) {
     // Save away the original text, so we still have it if the activity
     // needs to be killed while paused.
     outState.putString("my_text", sMyText);
     outState.putInt("my_int", nMyInt);
     Toast.makeText(this, "onSaveInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onSaveInstanceState", "onSaveInstanceState()");
}
 String sNewMyText = "";
 int nNewMyInt = 0;
 
 @Override
 protected void onRestoreInstanceState(Bundle savedInstanceState) {
     super.onRestoreInstanceState(savedInstanceState);
     // restore saved values
     sNewMyText = savedInstanceState.getString("my_text");
     nNewMyInt = savedInstanceState.getInt("my_int");
     Toast.makeText(this, "onRestoreInstanceState()", Toast.LENGTH_LONG).show();
     Log.i("onRestoreInstanceState", "onRestoreInstanceState()");
     
 }
}
18

long in java example | long-in-java-example


Android development

long is 64 bit signed type and used when int is not large enough to hold the value.

long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.


		// declaration and assignment of value type long
		long n = 22337203685477580L;
		// print formated value
		System.out.printf("The value of x is %d%n", n); // 22337203685477580
		System.out.format("%+,8d%n%n", n); // +22 337 203 685 477 580

		// declaring more variables in single statement
		long lo1 = 12L, lo2 = 56, lo3 = 1455555555589L;

		// long range of value
		System.out.println(Long.MAX_VALUE); // 9223372036854775807
		System.out.println(Long.MIN_VALUE); // -9223372036854775808

		// check if a string is a valid number in Java example
		// convert string to long Java example
		String sLong = "1288888888888888";
		long longParse = Long.parseLong(sLong);

		// convert strings to numbers
		long longFromString = (Long.valueOf(sLong)).longValue();

		// long to string in Java example code
		Long longObj = new Long(229999999999L);
		String str = longObj.toString();
		// else
		Long longS = 888888888888L;
		String strLong = longS.toString();

		// compare two long variables
		Long longComp1 = 5555L;
		if (longComp1.equals(55555555L))
			System.out.print("true");

		// compares the two specified long values in Java example

		int i = longS.compareTo(444444L); // -1 first < second
		// 0 first == second
		// 1 first > second
		System.out.print(i);
40

Spinner ComboBox DropDown set on selected item listener setOnItemSelectedListener Java Android example | spinner-combobox-set-on-selected-item-listener-setonitemselectedlistener-java-android-example


Spinner, ArrayAdapter, setOnItemSelectedListener, onItemSelected, setDropDownViewResource

MainClass.java

public class Vypocet extends Activity {
 Spinner   hSpinnerMetry;
// .......
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

	       hSpinnerMetry = (Spinner) findViewById(R.id.idSpinnerMetry);
	        ArrayAdapter<CharSequence> adapterMetry = ArrayAdapter.createFromResource(
	        		this, R.array.metry_array, android.R.layout.simple_spinner_item);
	        adapterMetry.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
	        hSpinnerMetry.setAdapter(adapterMetry);
			
	           hSpinnerMetry.setOnItemSelectedListener(
	                    new OnItemSelectedListener() {
	                        public void onItemSelected(
	                                AdapterView<?> parent, View view, int position, long id) {
	                        int nPos = position;
	                        }

	                        public void onNothingSelected(AdapterView<?> parent) {
	                        
	                        }
	                    });	        

      }
}



strings.xml


<string-array name="metry_array">
<item>m</item>
<item>dm</item>
<item>cm</item>
<item>mm</item>
</string-array>


211

The container JRE System Library JavaSE references non existing library | the-container-jre-system-library-javase-references-non-existing-library


Eclipse Error: The container JRE System Library JavaSE references non existing library QTJava.zip

Workaround:
Windows->Preferences->Java->Installed JRE
Press Add and select your JRE folder path for example:
c:\Program Files\Java\jre7\
and check your choice.

eclipse instaled jres path dialog


Editace: 2011-10-05 08:01:22
Počet článků v kategorii: 397
Url:switch-statement-java-basic-example

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