JavaScript Type Conversion Table
The table below shows the result of converting different JavaScript values to Number, String, and Boolean:
| Original Value |
Converted to Number |
Converted to String |
Converted to Boolean |
Try it |
|---|---|---|---|---|
| false | 0 | "false" | false | Try it » |
| true | 1 | "true" | true | Try it » |
| 0 | 0 | "0" | false | Try it » |
| 1 | 1 | "1" | true | Try it » |
| "0" | 0 | "0" | true | Try it » |
| "1" | 1 | "1" | true | Try it » |
| NaN | NaN | "NaN" | false | Try it » |
| Infinity | Infinity | "Infinity" | true | Try it » |
| -Infinity | -Infinity | "-Infinity" | true | Try it » |
| "" | 0 | "" | false | Try it » |
| "20" | 20 | "20" | true | Try it » |
| "twenty" | NaN | "twenty" | true | Try it » |
| [ ] | 0 | "" | true | Try it » |
| [20] | 20 | "20" | true | Try it » |
| [10,20] | NaN | "10,20" | true | Try it » |
| ["twenty"] | NaN | "twenty" | true | Try it » |
| ["ten","twenty"] | NaN | "ten,twenty" | true | Try it » |
| function(){} | NaN | "function(){}" | true | Try it » |
| { } | NaN | "[object Object]" | true | Try it » |
| null | 0 | "null" | false | Try it » |
| undefined | NaN | "undefined" | false | Try it » |
Note: Values in quotes ("") indicate string values. Values in red indicate values (some) programmers might not expect.
For a tutorial about JavaScript Type Conversion, read our JavaScript Type Conversion Tutorial.