JavaScript Type Conversions
The below table shows the result of converting a value to different primitive data types.
- The string values are quoted with double-quotes.
- The values in bold are those that most programmers do not expect.
| Value | Value Data Type | Converted to String | Converted to Number | Converted to Boolean |
| "" | string | "" | 0 | false |
| "0" | string | "0" | 0 | true |
| "1" | string | "1" | 1 | true |
| "10" | string | "10" | 10 | true |
| "ten" | string | "ten" | NaN | true |
| 0 | number | "0" | 0 | false |
| 1 | number | "1" | 1 | true |
| NaN | number | "NaN" | NaN | false |
| Infinity | number | "Infinity" | Infinity | true |
| -Infinity | number | "-Infinity" | -Infinity | true |
| false | boolean | "false" | 0 | false |
| true | boolean | "true" | 1 | true |
| [ ] | array | "" | 0 | true |
| [ 10 ] | array | "10" | 10 | true |
| [ 10, 20 ] | array | "10,20" | NaN | true |
| [ "ten" ] | array | "ten" | NaN | true |
| [ "ten", "twenty" ] | array | "ten,twenty" | NaN | true |
| null | null | "null" | 0 | false |
| undefined | undefined | "undefined" | NaN | false |
| function(){ } | function | "function(){ }" | NaN | true |
| { } | object | "[object Object]" | NaN | true |
Overall
We now know how a value can be converted to different primitive data types, like string, number, boolean, etc., in JavaScript.
Related Links
- JavaScript Tutorial
- JavaScript Examples