my mind has been destroyed :)

truth.js

var shouldTrueCount = 0;
var shouldTrue = [
    ' ',
    'a',
    true,
    1, {}
];
for (var i = 0; i < shouldTrue.length; i++) {
    if (shouldTrue[i]) {
        shouldTrueCount++;
    }
}
console.log('All that should be true are true: ' + (shouldTrueCount === shouldTrue.length));


var shouldFalseCount = 0;
var shouldFalse = [
    '',
    undefined,
    null,
    false,
    0
];

for (var i = 0; i < shouldFalse.length; i++) {
    if (!shouldFalse[i]) {
        shouldFalseCount++;
    }
}
console.log('All that should be false are false: ' + (shouldFalseCount === shouldFalse.length));