For more information, see Compiler warnings that are off by default.ĭisplays only warnings introduced in the version compiler version and earlier. This option helps ensure the fewest possible hard-to-find code defects.ĭisplays all warnings displayed by /W4 and all other warnings that /W4 doesn't include-for example, warnings that are off by default. For a new project, it may be best to use /W4 in all compilations. We recommend that you use this option to provide lint-like warnings. W4 displays level 1, level 2, and level 3 warnings, and all level 4 (informational) warnings that aren't off by default. W3 displays level 1, level 2, and level 3 (production quality) warnings. W2 displays level 1 and level 2 (significant) warnings.

W1 is the default setting in the command-line compiler.

Specifies the level of warnings to be generated by the compiler. The warning options and related arguments are described in the following tables: Option

The warning options specify which compiler warnings to display and the warning behavior for the entire compilation. Specifies how the compiler generates warnings for a given compilation.

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