float in Java example code
Android development
Java float is 32 bit single precision type and used when fractional precision calculation is required.
Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.
Java float is 32 bit single precision type and used when fractional precision calculation is required.
Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.
// declaration and assignment of value type float
float x = 18.41785f;
//print formated value
System.out.printf("The value of x is %.3f%n", x); // 18.418
// declaring more variables in single statement
float f1 = 12.4F, f2 = 564.5F, f3 = 14.589F;
// float range of value
System.out.println(Float.MIN_VALUE); // 4E-45
System.out.println(Float.MAX_VALUE); // 4028235E38
// is NaN Not-a-Number
float f = (float) Math.sqrt(-15);
boolean bNaN = Float.isNaN(f);
System.out.print(bNaN); // true
// check if a string is a valid number in Java example
// convert string to float Java example
String sF = "12.8";
float fParse = Float.parseFloat(sF);
// convert strings to numbers
String sFl = "15.48";
float fFromString = (Float.valueOf(sFl)).floatValue();
// float to string in Java example code
Float fObj = new Float(68.5);
String str = fObj.toString();
// else
Float fS = 11.6f;
String sFloat = fS.toString();
// compare two float variables
Float fComp1 = 4.3f;
if(fComp1.equals(4.3f))
System.out.print("true");
// compares the two specified float values in Java example
int i = Float.compare(11.5f, 11.7f); // -1 first < second
// 0 first == second
// 1 first > second
System.out.print(i);
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Další témata ....(Topics)
How add item to ArrayList, sort ArrayList, search find index of item in ArrayList, min(), max() Java basic example.
import java.util.ArrayList;
import java.util.Collections;
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = {"nothing", "Hello", "people"
, "bye-bye", "hello", "world!", "End" };
ArrayList<String> arrayList = new ArrayList<String>();
for(String s: arrayOfString)
arrayList.add(s);
Collections.sort(arrayList);
// foreach
for (String str: arrayList)
System.out.println(str);
Object objMin = Collections.min(arrayList);
System.out.println("Min is: " + objMin);
Object objMax = Collections.max(arrayList);
System.out.println("Max is: " + objMax);
int index = Collections.binarySearch(arrayList, "people");
System.out.println("Index of people is: " + index);
}
}
/*
End
Hello
bye-bye
hello
nothing
people
world!
Min is: End
Max is: world!
Index of people is: 5
*/
Issue:
When using New Activity wizard, ADT 20 asked to install Android Support library version 8 even though version 9 has been installed.
Pressing "Install/Update" then ADT popup a window downloading Support library, when finished nothing happen.
Pressing "Check Again" does nothing.
If i restarting Eclipse again this problem.
Notice: If you install new version ADT or update via SDK Manager, open SDK Manager standalone and close Eclipse.
Workaround:
- Close Eclipse
- Open SDK Manager standalone (c:\Program Files\Android\android-sdk-windows\SDK Manager.exe)
- Check the checkbox and uninstall Extras -> Android Support Library.
- Check again Extras -> Android Support Library and install it
- Restart Eclipse
- Try to create new project

When using New Activity wizard, ADT 20 asked to install Android Support library version 8 even though version 9 has been installed.
Pressing "Install/Update" then ADT popup a window downloading Support library, when finished nothing happen.
Pressing "Check Again" does nothing.
If i restarting Eclipse again this problem.
Notice: If you install new version ADT or update via SDK Manager, open SDK Manager standalone and close Eclipse.
Workaround:
- Close Eclipse
- Open SDK Manager standalone (c:\Program Files\Android\android-sdk-windows\SDK Manager.exe)
- Check the checkbox and uninstall Extras -> Android Support Library.
- Check again Extras -> Android Support Library and install it
- Restart Eclipse
- Try to create new project


How install Android emulator on PC
//developer.android.com/sdk/installing.html
Download links:
Java Development Kit JDK download
Eclipse download
Android SDK download
//developer.android.com/sdk/installing.html
Download links:
Java Development Kit JDK download
Eclipse download
Android SDK download
ScrollTo(), getTop(), getBottom(), getLeft(), getRight(), ScrollView, LinearLayout Android Java xml example.
How get position of a View.
MainClass.java
main.xml
How get position of a View.
MainClass.java
/*
public void scrollTo (int x, int y)
Since: API Level 1
Set the scrolled position of your view. This will cause a call to onScrollChanged(int, int, int, int) and the view will be invalidated.
This version also clamps the scrolling to the bounds of our child.
Parameters
x the x position to scroll to
y the y position to scroll to
*/
// sroll to top of hscrollViewMain
ScrollView hscrollViewMain = (ScrollView)findViewById(R.id.scrollViewMain);
hscrollViewMain.scrollTo(0, 0); // scroll to application top
// get position of a View
EditText hEdit = (EditText)findViewById(R.id.username_edit);
int nY_Pos = hEdit.getTop(); // getBottom(); X_pos getLeft(); getRight();
// scroll to top of hEdit
hscrollViewMain.scrollTo(0,nY_Pos);
main.xml
<LinearLayout
xmlns:android="//schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<ScrollView
android:id="@*id/scrollViewMain"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical"
android:paddingTop="5dip"
android:paddingBottom="13dip"
android:paddingLeft="20dip"
android:paddingRight="20dip">
<TextView
android:id="@+id/message"
android:textAppearance="?android:attr/textAppearanceSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="5dip" />
<TextView
android:textAppearance="?android:attr/textAppearanceSmall"
android:textStyle="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/login_activity_username_label" />
<EditText
android:id="@+id/username_edit"
android:singleLine="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:minWidth="250dip"
android:scrollHorizontally="true"
android:capitalize="none"
android:autoText="false"
android:inputType="textEmailAddress" />
</LinearLayout>
</ScrollView>
</LinearLayout>
Table of usability of mobile phones with Android – February 2012 - (application Sky Map)
1 | Samsung Galaxy S2 | 6.3% |
2 | HTC Desire HD | 3.5% |
3 | HTC Evo 4G | 3.4% |
4 | Samsung Galaxy Ace | 2.1% |
5 | Samsung Galaxy S (SCH-I500) | 2.1% |
6 | Samsung Galaxy S (GT-I9000) | 2.1% |
7 | HTC Incredible 2 | 2.0% |
8 | Motorola Droid X | 1.9% |
9 | Motorola Droid RAZR | 1.9% |
10 | HTC Sensation 4G | 1.7% |
Editace: 2011-09-26 20:49:50
Počet článků v kategorii: 396
Url:float-in-java-example-code