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Is there any List/Sequence built-in that behaves like map and provides the element's index as well?
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Scala List indexOf() method with example. The indexOf() method is utilized to check the index of the element from the stated list present in the method as argument. Return Type: It returns the index of the element present in the argument.
We can insert new key-value pairs in a mutable map using += operator followed by new pairs to be added or updated.
To convert a list into a map in Scala, we use the toMap method. We must remember that a map contains a pair of values, i.e., key-value pair, whereas a list contains only single values. So we have two ways to do so: Using the zipWithIndex method to add indices as the keys to the list.
I believe you're looking for zipWithIndex?
scala> val ls = List("Mary", "had", "a", "little", "lamb") scala> ls.zipWithIndex.foreach{ case (e, i) => println(i+" "+e) } 0 Mary 1 had 2 a 3 little 4 lamb From: http://www.artima.com/forums/flat.jsp?forum=283&thread=243570
You also have variations like:
for((e,i) <- List("Mary", "had", "a", "little", "lamb").zipWithIndex) println(i+" "+e) or:
List("Mary", "had", "a", "little", "lamb").zipWithIndex.foreach( (t) => println(t._2+" "+t._1) ) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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