Which function extracts a substring by specifying a starting position and length (distinct from Mid)?

Which function extracts a substring by specifying a starting position and length (distinct from Mid)?

• A. Left
• B. Mid
• C. Upper
• D. Substring

Answer: (D)

The idea being tested is how to pull out a portion of a string by giving where to start and how many characters to take. The function that does this is Substring. It takes the string, a starting position, and a length, and returns exactly that slice of characters. This is a common pattern in SQL and many programming languages, expressed as SUBSTRING(string, start, length). For example, SUBSTRING('Database', 2, 4) returns the characters starting at position 2 for 4 characters, yielding "ATAB". This differs from Left (which grabs characters from the left edge), Right (from the right edge), and Upper (which changes case), and it’s distinct from Mid, which is a different function name used in some languages for a similar idea.

The idea being tested is how to pull out a portion of a string by giving where to start and how many characters to take. The function that does this is Substring. It takes the string, a starting position, and a length, and returns exactly that slice of characters. This is a common pattern in SQL and many programming languages, expressed as SUBSTRING(string, start, length). For example, SUBSTRING('Database', 2, 4) returns the characters starting at position 2 for 4 characters, yielding "ATAB". This differs from Left (which grabs characters from the left edge), Right (from the right edge), and Upper (which changes case), and it’s distinct from Mid, which is a different function name used in some languages for a similar idea.