JavaScript 类型转换
JavaScript 类型转换表
下表显示了将不同的 JavaScript 值转换为 Number、String 和 Boolean 的结果:
| 原始值 | 转换为数字 | 转换为字符串 | 转换为布尔值 | 试一试 |
|---|---|---|---|---|
| false | 0 | "false" | false | 试一试 |
| true | 1 | "true" | true | 试一试 |
| 0 | 0 | "0" | false | 试一试 |
| 1 | 1 | "1" | true | 试一试 |
| "0" | 0 | "0" | true | 试一试 |
| "1" | 1 | "1" | true | 试一试 |
| NaN | NaN | "NaN" | false | 试一试 |
| Infinity | Infinity | "Infinity" | true | 试一试 |
| -Infinity | -Infinity | "-Infinity" | true | 试一试 |
| "" | 0 | "" | false | 试一试 |
| "20" | 20 | "20" | true | 试一试 |
| "twenty" | NaN | "twenty" | true | 试一试 |
| [ ] | 0 | "" | true | 试一试 |
| [20] | 20 | "20" | true | 试一试 |
| [10,20] | NaN | "10,20" | true | 试一试 |
| ["twenty"] | NaN | "twenty" | true | 试一试 |
| ["ten","twenty"] | NaN | "ten,twenty" | true | 试一试 |
| function(){} | NaN | "function(){}" | true | 试一试 |
| { } | NaN | "[object Object]" | true | 试一试 |
| null | 0 | "null" | false | 试一试 |
| undefined | NaN | "undefined" | false | 试一试 |
注意:引号 ("") 中的值表示字符串值。红色值表示程序员可能不希望的值。
如需更多 JavaScript 类型转换的知识,请阅读我们的 JavaScript 类型转换教程。