doc: update question 467 substr vs substring #298

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Expand Up		@@ -8845,8 +8845,19 @@ The execution context is created when a function is called. The function's code
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		467. ### What is the difference between substring and substr methods?
	Both substring() and substr() are string methods, which are used to find substring of a given string. But there are some notable differences with their usage,

	There are subtle differences between the substring() and substr() methods, so you should be careful not to get them confused.

	- The two parameters of substr() are start and length, while for substring(), they are start and end.
	- substr()'s start index will wrap to the end of the string if it is negative, while substring() will clamp it to 0.
	- Negative lengths in substr() are treated as zero, while substring() will swap the two indexes if end is less than start.

	Furthermore, substr() is considered a legacy feature in ECMAScript, so it is best to avoid using it if possible.

	```javascript
	const text = "Mozilla";
	console.log(text.substring(2, 5)); // "zil"
	console.log(text.substr(2, 3)); // "zil"
	```

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