Which option correctly matches a string that starts with 'a' and ends with 'z', with any number of characters in between?^a*z$a*z^a.*z$a.+z

To solve the problem of matching a string that starts with 'a' and ends with 'z' with any number of characters in between, we need to analyze the given options using regular expression syntax.

Break Down the Problem

1. Identify Requirements: The string must start with 'a', end with 'z', and can have zero or more characters in between.
2. Regular Expression Structure: We need to use:
   • ^ to indicate the start of the string.
   • .* to match any characters (including none) in between.
   • $ to indicate the end of the string.

Relevant Concepts

1. Regular Expressions:
   • ^ : asserts the start of the string.
   • . : matches any character.
   • * : matches zero or more occurrences of the preceding element.
   • z : matches the character 'z'.
   • $ : asserts the end of the string.

Analysis and Detail

1. The correct regular expression must follow the structure ^a.*z$:
   • ^a ensures the string starts with 'a'.
   • .* allows for any characters (including none) between 'a' and 'z'.
   • z$ ensures that the string ends with 'z'.

Verify and Summarize

After analyzing each option:

• ^a*z$: This matches 'a' repeated 0 or more times and then 'z', which doesn’t fit our requirement.
• a*z$: Similar to the above, it matches 'a' repeated, not necessarily indicating it starts with 'a' alone.
• ^a.*z$: This matches a string starting with 'a', any characters in between, and ending with 'z', which fits our requirements perfectly.
• a.+z: This requires at least one character between 'a' and 'z', which doesn't meet the condition for zero characters allowed.

Final Answer

The correct option is ^a.*z$.