each is different from map and collect, but map and collect are the same (technically map is an alias for collect, but in my experience map is used a lot more frequently). each performs the enclosed block for each element in the (Enumerable) receiver: [1,2,3,4].each {|n| puts n*2} # Outputs: # 2 # 4 # … Read more
You add: using System.Linq; at the top of your source and make sure you’ve got a reference to the System.Core assembly. Count() is an extension method provided by the System.Linq.Enumerable static class for LINQ to Objects, and System.Linq.Queryable for LINQ to SQL and other out-of-process providers. EDIT: In fact, using Count() here is relatively inefficient … Read more
As simple as this: Stream.empty()
Array#each executes the given block for each element of the array, then returns the array itself. Array#map also executes the given block for each element of the array, but returns a new array whose values are the return values of each iteration of the block. Example: assume you have an array defined thusly: arr = … Read more
The collection used in foreach is immutable. This is very much by design. As it says on MSDN: The foreach statement is used to iterate through the collection to get the information that you want, but can not be used to add or remove items from the source collection to avoid unpredictable side effects. If … Read more
If you like to know Index of each iteration you could use .each_with_index hash.each_with_index { |(key,value),index| … }
It’s certainly not a bug. It’s behaving exactly as documented: true if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false. Now you can argue about whether or not it should work that way (it seems fine to me; every element of the … Read more
The Zip operator merges the corresponding elements of two sequences using a specified selector function. var letters= new string[] { “A”, “B”, “C”, “D”, “E” }; var numbers= new int[] { 1, 2, 3 }; var q = letters.Zip(numbers, (l, n) => l + n.ToString()); foreach (var s in q) Console.WriteLine(s); Ouput A1 B2 C3
An enumerable property is one that can be included in and visited during for..in loops (or a similar iteration of properties, like Object.keys()). If a property isn’t identified as enumerable, the loop will ignore that it’s within the object. var obj = { key: ‘val’ }; console.log(‘toString’ in obj); // true console.log(typeof obj.toString); // “function” … Read more
You can do [5, 10].min or [4, 7].max They come from the Enumerable module, so anything that includes Enumerable will have those methods available. v2.4 introduces own Array#min and Array#max, which are way faster than Enumerable’s methods because they skip calling #each. @nicholasklick mentions another option, Enumerable#minmax, but this time returning an array of [min, … Read more