| Value | Type |
|---|---|
| 0 | Number |
| NaN (not a number) | Number |
| ” | String |
| false | Boolean |
| null | Object |
| undefined | Undefined |
Table taken from Douglas Crockford’s JavaScript: The Good Parts
Undefined
Undefined is the absence of a value, not an empty value.
| Value | Type |
|---|---|
| 0 | Number |
| NaN (not a number) | Number |
| ” | String |
| false | Boolean |
| null | Object |
| undefined | Undefined |
Table taken from Douglas Crockford’s JavaScript: The Good Parts
Undefined is the absence of a value, not an empty value.