String handling in Java

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Across
  1. 3. Checks substring
  2. 8. Converts to uppercase
  3. 9. Returns character at index
  4. 10. Returns length of string
Down
  1. 1. Replaces characters
  2. 2. Joins two strings
  3. 4. Finds position
  4. 5. Compares two strings
  5. 6. Converts to lowercase
  6. 7. Extracts part of string