Monday, February 27, 2012

if & else statements


I'm looking for some help with a little problem I'm having. Basically i have a "if & else" statement in my app but I want to add another "if" statement that checks for a file then for certain line of text in that file. But I am unsure of how to do this.



  • on "if" check if file exists

  • on "if" check if file exists but DOES NOT contain a certain line of text

  • on "else" do something



here is what i i have




if(file.exists()) {
do this
} else {
do this
}

3 comments:

  1. It sounds like you either need:

    if (file.exists() && readFileAndCheckForWhatever(file)) {
    // File exists and contains the relevant word
    } else {
    // File doesn't exist, or doesn't contain the relevant word
    }


    or

    if (file.exists()) {
    // Code elided: read the file...
    if (contents.contains(...)) {
    // File exists and contains the relevant word
    } else {
    // File exists but doesn't contain the relevant word
    }
    } else {
    // File doesn't exist
    }


    or reversing the logic of the previous one to flatten it

    if (!file.exists()) {
    // File doesn't exist
    } else if (readFileAndCheckForWhatever(file)) {
    // File exists and contains the relevant word
    } else {
    // File exists but doesn't contain the relevant word
    }

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  2. Unless I am missing something, couldn't you just be using else if?

    else if((file.exists())&&(!file.contains(Whatever))) { ... }

    File.contains would need to be exchanged for a function that actually checks the file, but you get the idea.

    ReplyDelete
  3. Maybe you mean something like:

    if(file.exists() && containsLine(file))
    {
    // do something
    }
    else
    {
    // do something else
    }

    public boolean containsLine(File f)
    {
    // do the checking here
    }

    ReplyDelete