Learn to love the JavaScript falsy conditions

Here is a quick tip for JavaScript falsy conditions for programmers or for people who come from Java or C#.

In Java and C# when we thinks of using a compare conditions in a if statements, we tend to use something along the line of:

if(val != null && val.length > 0) {
  //do stuff
}

We tend to bring this baggage of knowledge to JavaScript also, but it is not necessary. In JavaScript one can simply use the conditionals as below.

if(val) {
 //do something
}

Here is a table that will show you what could be the values of val that would translate to false.

Here is some sample code if you wish to test out falsy in JavaScript.

function testFalsy(val) {
  if(val) {
    console.log("True");
  } else {
    console.log("Falsy");
  }
}

testFalsy(true); // Output: True

testFalsy({}); // Output: True

testFalsy([]); // Output: True

testFalsy("hello world"); // Output: True

testFalsy(3.14); // Output: True

testFalsy(new Date()); // Output: True

testFalsy(false); // Output: Falsy

testFalsy(null); // Output: Falsy

testFalsy(undefined); // Output: Falsy

testFalsy(NaN); // Output: Falsy

testFalsy(0); // Output: Falsy

logTruthiness(""); // Output: Falsy

Learning these fundamental idioms in JavaScript allows one to write cleaner Javascript code.