{"id":5737,"date":"2023-02-08T00:01:55","date_gmt":"2023-02-08T08:01:55","guid":{"rendered":"https:\/\/c-for-dummies.com\/blog\/?p=5737"},"modified":"2023-02-04T10:57:42","modified_gmt":"2023-02-04T18:57:42","slug":"a-compact-for-loop-solution","status":"publish","type":"post","link":"https:\/\/c-for-dummies.com\/blog\/?p=5737","title":{"rendered":"A Compact for<\/em> Loop – Solution"},"content":{"rendered":"

I hope you were able to cram a lot of expressions into a for<\/em> loop statement, which is the challenge for this month’s Exercise<\/a>. Even if you know this trick, it’s important to understand it’s limitations — which is something I discovered during my research.
\n
\nHere is my solution, which uses an empty for<\/em> loop because all the statements that would otherwise roost inside a for<\/em> loop block are stuffed in the for<\/em> statement itself:<\/p>\n

2023_02-Exercise.c<\/a><\/h3>\n
\r\n#include <stdio.h>\r\n#include <stdlib.h>\r\n#include <time.h>\r\n\r\nint main()\r\n{\r\n    int r,count;\r\n\r\n    \/* loop until r = 99 *\/<\/span>\r\n    for( srand((unsigned)time(NULL)), r=0, count=1 ;\r\n            r!=99 ;\r\n            count++, r=rand()%100, printf(\"%3d : %2d\\n\",count,r)\r\n       )\r\n        ;\r\n    printf(\"%3d : %2d\\n\",count,r);\r\n\r\n    return(0);\r\n}\r\n<\/pre>\n
At Line 10, I split the three parts of a for<\/em> loop statement into three separate lines. First, the initialization:<\/p>\n
srand((unsigned)time(NULL)), r=0, count=1 ;<\/code><\/p>\n
You might expect to see the srand()<\/em> function in a statement before the for<\/em> loop. I stuck it into the looping statement on a whim and — guess what? — it works! Not every compiler allows you to stick a function into the for<\/em> loop statement in this manner, but clang<\/em> in the Windows Subsystem for Linux seems to be tolerant. The other two items are variable initialization expressions: r=0, count=1<\/code>. I tried to declare these variables in the for<\/em> loop statement, but the compiler threw a hissy fit.<\/p>\n
r!=99 ;<\/code><\/p>\n
The loop repeats as long as the value of r<\/code> (initialized to zero) isn’t equal to 99. This expression is typical for a for<\/em> loop termination, nothing fancy.<\/p>\n
The final part of the for<\/em> loop statement contains three expressions that normally would appear in the for<\/em> loop block:<\/p>\n
count++, r=rand()%100, printf(\"%3d : %2d\\n\",count,r)<\/code><\/p>\n
Variable count<\/code> is incremented. A random value r<\/code> is fetched in the range zero through 99. A printf()<\/em> statement outputs the program’s progress. Some compilers may balk at setting an assignment expression (r=rand()%100<\/code> into a for<\/em> loop statement. Even so, the point of this exercise is to condense the loop as much as you can. If the compiler doesn’t allow it, but you tried it anyway, give yourself a C For Dummies<\/em> bonus point.<\/p>\n
The final printf()<\/em> statement is required to output the value 99 after it’s encountered. Otherwise, the loop ends before this value is output.<\/p>\n
I hope your solution met with success and you perhaps learned a bit about how whacky you can get with a for<\/em> statement. I wouldn’t cram so much stuff into the statement for the programs I write. Yet, doing so is allowed (by some compilers) and a fun way to prove how ridiculously cryptic the C programming language can be.<\/p>\n","protected":false},"excerpt":{"rendered":"
I hope you were able to cram a lot of expressions into a for loop statement, which is the challenge for this month’s Exercise. Even if you know this trick, it’s important to understand it’s limitations — which is something … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-5737","post","type-post","status-publish","format-standard","hentry","category-solution"],"_links":{"self":[{"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/5737","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5737"}],"version-history":[{"count":3,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/5737\/revisions"}],"predecessor-version":[{"id":5748,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/5737\/revisions\/5748"}],"wp:attachment":[{"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5737"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5737"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c-for-dummies.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}