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Introduction
Like most computer languages, JavaScript supports Boolean data types; values which can be set to true or false. In addition, everything in JavaScript has an inherent Boolean value, generally known as either truthy or falsy:
Falsy
The following values are always falsy:
| false | |
| 0 | A Number with value zero, including 0.0. |
| NaN | A special Number value meaning Not-a-Number. |
| '' or "" | An empty string. |
| null | |
| undefined | Any undefined value, including special value undefined. |
Truthy
Everything else is truthy, for example:
| true | |
| Other Number values | Any non-0, non-NaN Number, including Infinity - a special value, like NaN. |
| A non-empty string | Any non-empty string, including 'false', '0' etc. |
| An Object | Any Object, Array etc objects, empty or not. |
| A Function | Any function. |
| etc |