Something like this would do: xargs cat <filenames.txt The xargs program reads its standard input, and for each line of input runs the cat program with the input lines as argument(s). If you really want to do this in a loop, you can: for fn in `cat filenames.txt`; do echo “the next file is $fn” … Read more
The nice thing with C++11 (previously called C++0x), is that this tiresome debate will be settled. I mean, no one in their right mind, who wants to iterate over a whole collection, will still use this for(auto it = collection.begin(); it != collection.end() ; ++it) { foo(*it); } Or this for_each(collection.begin(), collection.end(), [](Element& e) { … Read more
Since you are iterating over an indexable collection (lists, etc.), I presume that you can then just iterate with the indices of the elements: IntStream.range(0, params.size()) .forEach(idx -> query.bind( idx, params.get(idx) ) ) ; The resulting code is similar to iterating a list with the classic i++-style for loop, except with easier parallelizability (assuming, of … Read more
The .length property only tracks properties with numeric indexes (keys). You’re using strings for keys. You can do this: var arr_jq_TabContents = {}; // no need for an array arr_jq_TabContents[“Main”] = jq_TabContents_Main; arr_jq_TabContents[“Guide”] = jq_TabContents_Guide; arr_jq_TabContents[“Articles”] = jq_TabContents_Articles; arr_jq_TabContents[“Forum”] = jq_TabContents_Forum; for (var key in arr_jq_TabContents) { console.log(arr_jq_TabContents[key]); } To be safe, it’s a good … Read more
They are not one and the same. Let me explain the difference. forEach: This iterates over a list and applies some operation with side effects to each list member (example: saving every list item to the database) and does not return anything. map: This iterates over a list, transforms each member of that list, and … Read more
Every occurence of “foreach” I’ve seen (PHP, C#, …) does basically the same as pythons “for” statement. These are more or less equivalent: // PHP: foreach ($array as $val) { print($val); } // C# foreach (String val in array) { console.writeline(val); } // Python for val in array: print(val) So, yes, there is a “foreach” … Read more
If you are just wandering over the collection to read all of the values, then there is no difference between using an iterator or the new for loop syntax, as the new syntax just uses the iterator underwater. If however, you mean by loop the old “c-style” loop: for(int i=0; i<list.size(); i++) { Object o … Read more
Yes, NSDictionary supports fast enumeration. With Objective-C 2.0, you can do this: // To print out all key-value pairs in the NSDictionary myDict for(id key in myDict) NSLog(@”key=%@ value=%@”, key, [myDict objectForKey:key]); The alternate method (which you have to use if you’re targeting Mac OS X pre-10.5, but you can still use on 10.5 and … Read more
This is the only difference: each: irb> [1,2,3].each { |x| } => [1, 2, 3] irb> x NameError: undefined local variable or method `x’ for main:Object from (irb):2 from :0 for: irb> for x in [1,2,3]; end => [1, 2, 3] irb> x => 3 With the for loop, the iterator variable still lives after … Read more
.forEach already has this ability: const someArray = [9, 2, 5]; someArray.forEach((value, index) => { console.log(index); // 0, 1, 2 console.log(value); // 9, 2, 5 }); But if you want the abilities of for…of, then you can map the array to the index and value: for (const { index, value } of someArray.map((value, index) => … Read more