[Android] String equal比較兩字串是否相同

示範

XML

xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:id="@+id/t1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
android.support.constraint.ConstraintLayout>

JAVA

public class MainActivity extends AppCompatActivity  {
    int c=0;
    TextView t1;
    String s1="apple";
    String s2="bird";
    String s3="apple";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        t1=(TextView)findViewById(R.id.t1);
if(s1.equals(s2)){
    c++;
}else if(s1.equals(s3)){
    c++;
}else{
    c=0;
}
t1.setText(""+c);
    }
}