delete: interview questions & migration guide

Author: danieldanielecki

data/blog/software-development/web-development/frontend/javascript/slice-vs-substring-vs-substr-complete-javascript-string-methods-comparison.mdx

@@ -28,8 +28,6 @@ This comprehensive guide will provide an in-depth exploration of each method, co
 - **Type coercion behavior** and how non-number values are handled
 - **Unicode and special character handling** for international strings
 - **Integration patterns** with other JavaScript string methods
-- **Migration strategies** for legacy codebases
-- **Interview preparation** with common questions and answers
 
 By the end of this article, you'll not only understand each method's behavior but also gain the expertise to choose the right method for your specific use case, write more robust code, and debug string manipulation issues effectively.
 
@@ -693,7 +691,7 @@ string.substr(startIndex, length)
 - **Not Part of ECMAScript Standard**: Though widely supported, it's not part of the official JavaScript specification
 - **Can Be Replaced**: All use cases can be handled with `slice()` instead
 
-**Recommendation**: Use `slice()` instead of `substr()` in all cases. See migration examples in the section below.
+**Recommendation**: Use `slice()` instead of `substr()` in all cases.
 
 ### `substr()` Examples
 
@@ -1153,154 +1151,6 @@ console.timeEnd('substring');
 // Choose based on functionality, not performance
 ```
 
-## Migration Guide: Replacing substr() and substring()
-
-If you have existing code using `substr()` or `substring()`, here's how to migrate to `slice()`:
-
-### Replacing substr()
-
-```javascript
-// OLD: Using substr()
-const result1 = str.substr(start, length);
-
-// NEW: Using slice()
-const result1 = str.slice(start, start + length);
-
-// OLD: Using substr() with negative start
-const result2 = str.substr(-n);
-
-// NEW: Using slice() with negative index
-const result2 = str.slice(-n);
-
-// OLD: Using substr() with negative start and length
-const result3 = str.substr(-6, 3);
-
-// NEW: Using slice() - calculate start index
-const startIndex = str.length + (-6); // or use Math.max(0, str.length - 6)
-const result3 = str.slice(startIndex, startIndex + 3);
-```
-
-### Replacing substring()
-
-```javascript
-// OLD: Using substring() (works the same when start < end)
-const result1 = str.substring(start, end);
-
-// NEW: Using slice() (drop-in replacement)
-const result1 = str.slice(start, end);
-
-// OLD: Using substring() with swapped arguments (common mistake)
-const result2 = str.substring(end, start); // This swaps automatically!
-
-// NEW: Using slice() - be explicit about what you want
-const result2 = str.slice(Math.min(start, end), Math.max(start, end));
-// OR if you really want swapping behavior:
-const result2 = start > end ? str.slice(end, start) : str.slice(start, end);
-```
-
-### Common Interview Questions and Answers
-
-Here are typical interview questions about these methods:
-
-#### Question 1: What's the difference between slice() and substring()?
-
-**Answer:**
-- `slice()` supports negative indices (counts from end), `substring()` treats negatives as 0
-- `slice()` returns empty string if start > end, `substring()` swaps the arguments
-- `slice()` is more modern and recommended, `substring()` is legacy but still supported
-- `slice()` behavior is consistent with `Array.slice()`
-
-#### Question 2: How would you get the last 3 characters of a string?
-
-**Answer:**
-```javascript
-// Method 1: Using slice() with negative index (RECOMMENDED)
-const last3 = str.slice(-3);
-
-// Method 2: Using slice() with calculated index
-const last3 = str.slice(str.length - 3);
-
-// Method 3: Using substring() (less intuitive)
-const last3 = str.substring(str.length - 3);
-
-// Method 4: Using substr() (deprecated, don't use)
-const last3 = str.substr(-3); // DON'T USE
-```
-
-#### Question 3: What happens when you call substring(5, 2)?
-
-**Answer:**
-The arguments are automatically swapped, so `substring(5, 2)` becomes `substring(2, 5)`. This returns the substring from index 2 to index 4 (exclusive of 5).
-
-In contrast, `slice(5, 2)` would return an empty string because `slice()` doesn't swap arguments.
-
-### Working with Template Literals and Dynamic Strings
-
-```javascript
-// Extracting from template literals
-const name = "John Doe";
-const age = 30;
-const template = `Hello, ${name}! You are ${age} years old.`;
-
-// Extract name from template
-const nameStart = template.indexOf(name);
-const extractedName = template.slice(nameStart, nameStart + name.length);
-console.log(extractedName); // "John Doe"
-
-// Extracting dynamic portions
-function extractVariable(template, variable) {
-  const start = template.indexOf(variable);
-  if (start === -1) return null;
-  return template.slice(start, start + variable.length);
-}
-```
-
-### Error Handling and Validation Patterns
-
-```javascript
-// Robust extraction function with validation
-function safeExtract(str, start, end, method = 'slice') {
-  // Input validation
-  if (typeof str !== 'string') {
-    throw new TypeError('First argument must be a string');
-  }
-
-  if (str.length === 0) {
-    return '';
-  }
-
-  // Validate indices
-  const startNum = Number(start);
-  const endNum = end !== undefined ? Number(end) : undefined;
-
-  if (isNaN(startNum)) {
-    throw new TypeError('Start index must be a number');
-  }
-
-  if (end !== undefined && isNaN(endNum)) {
-    throw new TypeError('End index must be a number');
-  }
-
-  // Choose method
-  switch (method) {
-    case 'slice':
-      return str.slice(startNum, endNum);
-    case 'substring':
-      return str.substring(startNum, endNum);
-    default:
-      throw new Error(`Unknown method: ${method}`);
-  }
-}
-
-// Usage with error handling
-try {
-  const result = safeExtract("Hello World", 0, 5, 'slice');
-  console.log(result); // "Hello"
-} catch (error) {
-  console.error('Extraction error:', error.message);
-}
-```
-
 ## Browser Compatibility
 
 All three methods are widely supported: