logical-operators.js

// Binary Logical Operators 
// AND &&
//  OR ||
// creating compound if statements

let ingredients = ['ham', 'onion', 'tomato'];

let sandwichHas = function(ingredient){
    for(let i of ingredients){
        if( i == ingredient){
            return true;
        }
    }
    return false;
    //if this line omitted it returns undefined
    //which is also a falsey value
}

if( sandwichHas('ham') ||  sandwichHas('chicken') || sandwichHas('beef')){
    console.log('Sandwich has meat')
}else{
    console.log('No meat')   
}

if( sandwichHas('lettuce') && sandwichHas('onion') ){
    console.log('it has both')
}else{
    console.log('it has NOT both but maybe one of them')
}

if( (sandwichHas('cheddar') && sandwichHas('onion')) || 
  sandwichHas('onion') && sandwichHas('tomato')){
    console.log('cheese and lettuce ... OR onion')
}else{
    console.log('failed final test')
}