Is it possible to assign and at the same time perform a comparison in an if clause in Java?
For example:
String linha = leitor.readLine();
String saida = "";
if (linha = leitor.readLine()) {
saida += "\n";
}
This does not seem to work.
How would I do it?
You do not show the condition you want to test on if , let's call it condicao :
if ((linha = leitor.readLine()) == condicao) {
saida += "\n";
}
The above code will first assign the linha the value of readLine and then make the comparison with the condicao .
It does not work directly because java does not allow automatic conversion to boolean. But you can do the following:
String linha = leitor.readLine();
String saida = "";
if ( (linha = leitor.readLine()) != null) {
saida += "\n";
}
As in C and C ++, the assignment is an expression whose value is that of the variable that has just been assigned. In this case the type is String , which is not accepted within if . With the set of parentheses, we can isolate the value of the assignment and compare it with null to know if the operation occurred as expected.