int comparison always returns true?

[thomasjbs]

I can't figure this out - new to java, but code appears to be ok.

I'm looking for a string within lines of text returned from a system
command. I get all the output back - no problem. But when I try to
do something based on indexOf, it always returns true:

Here is output from System.out.println statements showing the text
does *not* exist in the output (and another example showing it does)

Here is the code to search for it. On



int tf = 0;
boolean textfound = false;

// Loop through lines of text with Try and readLine...
{
tf = inputLine.indexOf("FINDTHISSTRING");
System.out.println(tf);

if ( tf > -1 );
{
textfound = true;
}
}


I also tried " tf == 0 ".

Example of Failure to find Text
======================

-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1


Example of case where FIND text Exists:
==============================

-1
-1
-1
-1
-1
-1
0 Found it here
-1
0 and Here
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1

 

[thomasjbs]

The semicolon after the parenthesis (on the first line) is the end of
the "if"-statement. The "{ textfound = true; }" block following it is
thus not affected by the conditional. It's just a stand-alone block.

- Logan

lol

I work in so many different languages with different syntax that I
didn't even notice it.

I skipped over it about 50 times. Its so obvious...now. I think the
braces give my single, unconditional assignment a nice emphasis.

Thanks for your help. It worked perfectly after removing the
semicolon.

 

[Arne Vajhøj]

I work in so many different languages with different syntax that I
didn't even notice it.

There are many languages where the same problem is possible.

Arne

 

[Roedy Green]

I can't figure this out - new to java, but code appears to be ok.

I'm looking for a string within lines of text returned from a system
command. I get all the output back - no problem. But when I try to
do something based on indexOf, it always returns true:

Here is output from System.out.println statements showing the text
does *not* exist in the output (and another example showing it does)

Here is the code to search for it. On

I would write that more tersely as:

final boolean found = inputLine.indexOf("FINDTHISSTRING") >= 0;

 

[Roedy Green]

int tf = 0;
boolean textfound = false;

// Loop through lines of text with Try and readLine...
{
tf = inputLine.indexOf("FINDTHISSTRING");
System.out.println(tf);

if ( tf > -1 );
{
textfound = true;
}
}

You have not show the loop just hinted there is one. But I suspect
what you did was set textFound false only once. Once it goes true, it
stays true.

 

[Roedy Green]

if ( tf > -1 );
{
textfound = true;
}

If you ran that through a lint in your IDE it would warn you of the
empty if-true clause.

 

[Mike Schilling]

There are many languages where the same problem is possible.

All the C-based ones, at least.