Opposite of .contains (does not contain)

Solution 1:

It seems that Luiggi Mendoza and joey rohan both already answered this, but I think it can be clarified a little.

You can write it as a single if statement:

if (inventory.contains("bread") && !inventory.contains("water")) {
    // do something
}

Maybe

if (inventory.contains("bread") && !inventory.contains("water"))

if (inventory.contains("bread")) {
    if (!inventory.contains("water")) {
        // do something here
    } 
}