I divided 124/13. but the app forced close. this is my code:
Float x =Float.valueOf(a.getText().toString()); Float y =Float.valueOf(b.getText().toString()); BigDecimal xx= new BigDecimal (x); BigDecimal yy= new BigDecimal (y); BigDecimal rx= xx.divide(yy); res.setText("=" + rx); It is possible that the app is crashing, because BigDecimal.toString() does something unexpected. Also a, or b or rx may be null.
In any way, I would consider using BigDecimal with the String constructor, such that no rounding errors occur:
String x = a.getText().toString(); String y = b.getText().toString(); BigDecimal xx = new BigDecimal(x); BigDecimal yy = new BigDecimal(y); BigDecimal rx = xx.divide(yy); res.setText("=" + rx.toPlainString()); Also write new BigDecimal(x) instead of new BigDecimal (x). Note the omitted space, that may be the very reason why your app crashes, it is not allowed in Java.
new BigDecimal (x) is perfectly legal Java syntax (though not recomended by Code Conventions)You have encountered:
java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result. Consider this example, which will yeld this exact exception:
BigDecimal x = new BigDecimal(1); BigDecimal y = new BigDecimal(3); BigDecimal result = x.divide(y); That's because there's no exact representation of 0.3333(3). What you need to do is to specify rounding and precision:
BigDecimal result = x.divide(y, 10 /*scale*/, RoundingMode.HALF_UP); System.out.println(result); //will print "0.3333333333" Also note that you should create the BigDecimal directly from String, as float is not a precise representation. Consider this:
String s = "0.123456789"; System.out.println(Float.parseFloat(s)); //prints 0.12345679 System.out.println(new BigDecimal(s)); //prints 0.123456789 It may be the case that you want an approximate result. Then just go with float or double only:
dobule x = Double.parseDouble(a.getText()); dobule y = Double.parseDouble(b.getText()); res.setText("=" + (x/y));