JavaScript has unique behaviours that can be puzzling. Let's go through some of them with examples to understand better.
1. Arrays Equal Strings
In JavaScript, comparing an array to a string using the equality operator (==) can lead to unexpected results:
When comparing a or b with c, JavaScript converts the arrays to strings, resulting in a comparison of '0,1,2' == '0,1,2', which is true. However, when comparing a and b, it checks for object reference equality, and since a and b refer to different arrays in memory, the result is false.
2. Numbers Are Sorted Alphabetically
JavaScript’s default sort method converts numbers to strings and sorts them lexicographically (alphabetically):
3. String Is Not a String
The typeof operator can be misleading when used with strings:
The typeof operator returns 'string' for string literals. However, instanceof checks for an instance of the String object wrapper, which is not the same as a string literal.
4. Null Comparisons
Comparing null can yield unintuitive results:
In relational comparisons, null is treated like 0. However, with non-strict equality (==), null is only equal to undefined and no other value.
Part 2: https://www.buymeacoffee.com/codecrumbs/the-weird-side-javascript-explained-part-2
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