09-types-null-undefined.md

Null and Undefined

• Used to express 'nothing' in JavaScript.

• If we declare a variable, and don't set anything to it, then it has value undefined.

    let dog;
    console.log(dog); // undefined

  When we try to access a variable that is created but not defined/set a value, we get undefined.

• null: value of nothing

    const somethingNull = null;
    // we have explicitly set the value to be nothing with null