{"id":938,"date":"2024-08-09T20:29:06","date_gmt":"2024-08-09T20:29:06","guid":{"rendered":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/?page_id=938"},"modified":"2025-01-26T19:12:48","modified_gmt":"2025-01-26T19:12:48","slug":"exceptions","status":"publish","type":"page","link":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/topics\/c-details\/exceptions\/","title":{"rendered":"Exceptions"},"content":{"rendered":"\n

<\/span>Exceptions<\/span><\/h2>\n\n\n\n

<\/span>What is the Problem?<\/span><\/h3>\n\n\n\n

Classes have their public interfaces, which traditionally have simply specified what happens under normal circumstances.<\/p>\n\n\n\n

But it\u2019s important to define how things work under exceptional<\/em> conditions, as well.<\/p>\n\n\n\n

Traditionally, C programmers have used a large set of inconsistent approaches towards indicating success or failure. Often, by returning special values from a function call – but the types of values vary all over the place! <\/p>\n\n\n\n

For example:<\/p>\n\n\n\n

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FILE *fp = <\/span>fopen<\/span>(<\/span>"myfile.dat"<\/span>, <\/span>"r"<\/span>);<\/span><\/span>\nif<\/span> (fp == <\/span>NULL<\/span>)<\/span><\/span>\n  <\/span>fprintf<\/span>(stderr, <\/span>"Failed to open file<\/span>\\n<\/span>"<\/span>);<\/span><\/span><\/code><\/pre><\/div>\n<\/div>\n\n\n\n
<\/div>\n<\/div>\n\n\n\n
or:<\/p>\n\n\n\n
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int<\/span> ch = <\/span>getchar<\/span>();<\/span><\/span>\nif<\/span> (ch == EOF)<\/span><\/span>\n  <\/span>exit<\/span>(<\/span>0<\/span>);<\/span><\/span><\/code><\/pre><\/div>\n<\/div>\n\n\n\n
<\/div>\n<\/div>\n\n\n\n
and so on…<\/p>\n\n\n\n
But this approach has problems:<\/p>\n\n\n\n