Ternary operators are a concise way to write conditional statements that have two possible outcomes. Rather than writing a longer series of if\/then\/else statements you can write one line that makes it clear what the two choices are.<\/p>\n
In this example from iOS, I use a string for direction\u2014either clockwise or counterclockwise\u2014and translate it to a number for use in the formula. That way I don’t have to remember whether -1 is clockwise or counterclockwise when calling the method. I can use natural language to call the method and let the ternary operator take care of the conversion to the value I need in my formula. And I can change my formula at a later date without having to go back and find all the method calls.<\/p>\n
Here\u2019s the method call and the operator
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\n- (void)spin:(NSString *)direction withDuration:(float)duration withScale:(float)scale {\n \n int rotation = ([direction isEqualToString:@"clockWise"] ? 1 : -1);\n<\/code><\/pre><\/p>\nAnd then use rotation later to determine which way the object rotates
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\nview.transform = CGAffineTransformRotate(CGAffineTransformScale(transform, 1.0, 1.0), rotation * 2*M_PI\/3);\n<\/code><\/pre><\/p>\nHere\u2019s another example, where I want to pass in a value, but make sure that it isn\u2019t less than one. In this case I\u2019m passing in an integer and rather than doing a series of complicated if\/then\/else statements I just put the ternary operator in where the integer goes.
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\nself.showRewards = [[ShowRewards alloc] initWithParentView:self.view withLevel:(rewardLevel > 0 ? rewardLevel : 1) ];\n<\/code><\/pre>
\nI also use it in PHP code for plurals. Something like this is what I use.
\n\n$text = "The update was successful. $recordsUpdated " . ($recordsUpdated > 1 ? 'records were updated.' : 'record was updated.');\necho $text;\n<\/code><\/pre><\/p>\nAnd I use it to write one set of code that works for two inputs. In this case I have a page that displays all of the titles that are downloadable from Gumroad. Since people are only interested in the Mac or Windows version, I put them on two different pages\u2014but I use the same code. The first part reads in the page type from the URL and puts up a title for Macintosh or Windows.<\/p>\n
\nif ( isset($_GET['page']) ) { $MacWin = mysql_real_escape_string($_GET['page']); } else { $MacWin = 'Win';} \n\necho "<div id='wideMargins'>";\n$MacintoshWindows = ($MacWin == 'Mac' ? 'Macintosh' : 'Windows');\necho "<h2 class='NewSection'>Download $MacintoshWindows Compatible Titles from Gumroad<\/h2>";\n<\/code><\/pre><\/p>\nThen in the SQL statements I pull the appropriate titles. My column names are GumroadURL_Mac and GumroadURL_Win so the $MacWin variable is substituted into the SELECT statement.
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\n$qry = "SELECT *\n FROM product, product_instance\n WHERE product.id = product_id\n AND GumroadURL_$MacWin IS NOT NULL\n ORDER BY name";\n<\/code><\/pre><\/p>\nI use a full ternary operator to get the right column from the row.
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\nfor ($i = 0; $i < $numRows; $i++) {\n $row = $res->fetch_array();\n $name = $row['name'];\n $tagline = $row['tagline'];\n $GumroadURL = ($MacWin == 'Mac' ? $row['GumroadURL_Mac'] :$row['GumroadURL_Win']);\n<\/code><\/pre><\/p>\nAs you can see, it makes the code much easier to read and in this example, I have one page of code that easily generates two web pages.<\/p>\n","protected":false},"excerpt":{"rendered":"
Ternary operators are a concise way to write conditional statements that have two possible outcomes. Rather than writing a longer series of if\/then\/else statements you can write one line that makes it clear what the two choices are. In this example from iOS, I use a string for direction\u2014either clockwise or counterclockwise\u2014and translate it to … Continue reading Ternary operator<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-1496","post","type-post","status-publish","format-standard","hentry","category-coding"],"_links":{"self":[{"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=\/wp\/v2\/posts\/1496","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1496"}],"version-history":[{"count":0,"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=\/wp\/v2\/posts\/1496\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1496"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1496"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wellgolly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1496"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}