拡張子 (kakuchoushi) Japanese meaning: file extension | KotomoraYou can tell the type of file by looking at its extension.
Changing the file extension may make the file unopenable.
Usage patterns
〈物〉の拡張子を変更するto change a file's extension
I changed the file's extension from .txt to .doc.
拡張子を表示するto show file extensions
〈物〉の拡張子を確認するto check a file's extension
I checked the attached file's extension before opening it.
I changed the settings so that file extensions are shown for all files.
