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"/>

1. File->Project Structure Ctrl + Alt + Shift + S



2. Select module and Dependencies Tab



3. Click on + PLUS button (right upper corner)



4. Select library


Click OK, OK

If you have to type frequently the same code you can create templates which can be activate via autocomplete with Ctrl + Space.

For example lets assume setOnClickListener body.

To create a template for this select the menu Window->Preferences and Open Java -> Editor -> Templates

Type name of template in Eclipse s editor and pres Ctrl+Space

[caption id="attachment_1114" align="alignleft" width="300" caption="Eclipse-show-template-proposals"][/caption]

Select your template from intellisense help and press Enter or double click on selected item.

[caption id="attachment_1116" align="alignleft" width="300" caption="Eclipse - select your template"][/caption]

	mIdButtonHome.setOnClickListener(new View.OnClickListener() {
		public void onClick(View v) {
			Intent browserIntent = new Intent(Intent.ACTION_VIEW,
					Uri.parse("//android.okhelp.cz/category/software/"));
			startActivity(browserIntent);
		}
	});

Quick help in Eclipse editor: select keyword and press Ctrl+1

import android.os.Build.VERSION;
//
int nSdkVersion = Integer.parseInt(Build.VERSION.SDK);
int nApiVersion = VERSION.SDK;

Platform Version	API Level
Android 4.0	14
Android 3.2	13
Android 3.1.x	12
Android 3.0.x	11
Android 2.3.4	10
Android 2.3.3	10
Android 2.3.2	9
Android 2.3.1	9
Android 2.3	9
Android 2.2.x	8
Android 2.1.x	7
Android 2.0.1	6
Android 2.0	5
Android 1.6	4
Android 1.5	3
Android 1.1	2
Android 1.0	1

float, double is NaN isNaN() isInfinite() Java Android example.

float f = 0.f;
boolean bIsNaN = Float.isNaN(f);
boolean bIsInfinite = Float.isInfinite(f);

 double d = Math.sqrt(-10);
 boolean b = Double.isNaN(d);