Difference between logical operators and or Java
Basic difference remember it!!!
if(TRUE && TRUE && TRUE) return TRUE otherwise FALSE
if(FALSE || FALSE || FALSE) return FALSE otherwise TRUE
Logical operator and &&
If all conditions/operands is TRUE return TRUE, otherwise return FALSE
Logical operator or ||
The logical OR operator (||) returns the boolean value true if either or both operands is true and returns false otherwise.
If one operands is TRUE, condition is TRUE:
rev
if(TRUE && TRUE && TRUE) return TRUE otherwise FALSE
if(FALSE || FALSE || FALSE) return FALSE otherwise TRUE
Logical operator and &&
If all conditions/operands is TRUE return TRUE, otherwise return FALSE
if( true and true and true){
// return true - do something
}
int a = 6;
if(a == 6 && a == 6 ) {
// if TRUE
// true && true return true, do something
}
if(a == 6 && a == 5){
// nothing, not attended
}else{
// true && false return false, or false && false return false
// do something
}
Logical operator or ||
The logical OR operator (||) returns the boolean value true if either or both operands is true and returns false otherwise.
If one operands is TRUE, condition is TRUE:
if(FALSE OR FALSE OR TRUE) return TRUE
if(FALSE OR TRUE OR FALSE) return TRUE
if(FALSE OR FALSE OR FALSE) return FALSE
int a = 6;
if(a==6 || a==5){ // TRUE || FALSE return TRUE
//if return TRUE
//one from operadns is TRUE return true, do something
}
if(a==5 || a==4){ // FALSE || FALSE return FALSE
// not attended
}else{
//if return FALSE, do something
}
rev
397LW NO topic_id
Další témata ....(Topics)
android:background="@android:color/transparent"
<LinearLayout
android:baselineAligned="false"
android:background="@android:color/transparent"
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<LinearLayout>
////////////////////////////
LinearLayout mLinearLayout1 = (LinearLayout)findViewById(R.id.linearLayout1);
mLinearLayout1.setBackgroundColor(Color.TRANSPARENT);
Try two way in Eclipse IDE:
1.) Import the library project into your Eclipse workspace.
Click File > Import,
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.
If project not visible with checkbox try next step as see below.
2.) Click
File > New > Other
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.
1.) Import the library project into your Eclipse workspace.
Click File > Import,
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.
If project not visible with checkbox try next step as see below.
2.) Click
File > New > Other
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.
public boolean isConnected() {
try {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
return cm.getActiveNetworkInfo().isConnectedOrConnecting();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("isConnected", e.getMessage());
Toast.makeText(getApplicationContext(), e.getMessage(),
Toast.LENGTH_LONG).show();
return false;
}
"id cannot be resolved or is not a field” error
If you copy project to workspace or some code from other project you can get this error.
Try remove or add import your R file:
Check xml files.
Clean project by menu Project-Clean
Maybe you have to create new project end copy old source files to new project folders.
If you copy project to workspace or some code from other project you can get this error.
Try remove or add import your R file:
import com.example.app.R
Check xml files.
Clean project by menu Project-Clean
Maybe you have to create new project end copy old source files to new project folders.
xml RelativeLayout Android example:
Eclipse graphical xml layout editor
[caption id="attachment_896" align="alignleft" width="261" caption="Relativelayout Eclipse graphical editor"]
[/caption]
res/layout/main.xml
Eclipse graphical xml layout editor
[caption id="attachment_896" align="alignleft" width="261" caption="Relativelayout Eclipse graphical editor"]
[/caption]
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/idLabel"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter word"/>
<EditText
android:id="@+id/idEntry"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@android:drawable/editbox_background"
android:layout_below="@id/idLabel"/>
<Button
android:id="@+id/idOk"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/idEntry"
android:layout_alignParentRight="true"
android:layout_marginLeft="10dip"
android:text="OK" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="@id/idOk"
android:layout_alignTop="@id/idOk"
android:text="Cancel" />
</RelativeLayout>
Editace Jana Žákovská : 2016-02-29 17:06:05
Počet článků v kategorii: 397
Url:difference-between-logical-operators-and-or-java
