javascript - using .slice method on an array -


I'm practicing the array of JavaScript Koan and I'm not fully understanding why these answers are correct. I have added my beliefs below, if someone can explain to me / tell me that I am wrong: 

  it should "slice arrays", function () {var array = [ Excerpt ([]];   
 
 Why do so Will not the least piece "jelly" begin with piece 3, how does the cut of 0 change it empty?   
  Hope (array.slice (3, 100)) .toEqual (["jelly"]);   
 
 If cut off If the index is beyond the current in the array, does it mean that all the indexes starting from 3 until the end of a new array array created from slices?   
  Expect (array.slice (5, 1)). ToEqual ([undefined];   
 
 Will this always be undefined if the start index is not present in the array?   
 });    
 
 
 The second argument is that App er is connected to a piece  
 e Think 
 from array.slice (lowest index, highest index) .  
 When you slide from index 3 to index 100, then an item (in your case), which has an index; Gt; = 3 more & lt; 100, then you get an array with one item when you try to take a piece from index 3 to index 0, then there can not be any such thing as index & gt; = 3 more & lt; 0, then you will get an empty array.  
 - Edit -  
 In addition,  array.slice ()  should never be undefined. It is one of the advantages of using it. If there is no matching value in the array, then you can only get back an empty array. Even if you call  var a = new array ()  and do not add any value for it, then call  a.slice (0,1)  will give you only an empty space, the array will also return an array of empty slices from the outside of the array range.  a.slice (250)  will be  [] , while  a [250]  will be undefined.

Comments

Post a Comment

Popular posts from this blog

Java - Error: no suitable method found for add(int, java.lang.String) -

I'm in the middle of homework work and I'm stuck. At this point in my code, I think that I should have a GUI window that opens and allows me to type "inserted text number". Notice is not going anywhere but at this point, If I pass through the problem then it will be in a linked list. I am getting two of the same error for the lines. Add (index, element); And I can not seem to get past it, there is no suitable method for the error "add (int, java. string string)". Code is below, please advise. To clarify - this will not be a method error because it is a linked list. There should not be any way involved. import java.awt. *; Import java.awt.event. *; Import javax.swing. *; Import java.util. *; Import java.util.Scanner; Import java.util.LinkedList; Public class TopTenList JFrame {Private TopTenList tt; See the Private JTextArea list; Private JTextField cmdTextField; Private JTextField resultsTestfield; // This GUI window is the code for the public toptist...
Read more

java - JPA TypedQuery: Parameter value element did not match expected type -

I am using JPA 2.0 and getting the following code in the DAO layer: Public Zero Test () {string key = "status"; String [] Conditions = {"A", "B"}; & Lt; TestTable & gt; Results = Search (Keys, Conditions); } Public listing & lt; TestTable & gt; Search (string key, object value error) {string sql = "test ndf to testlet and jade nand." + Key + "in:" + key; TypedQuery & LT; TestTable & gt; Query = entityManager.createQuery (SQL, TestTable.class); Query.setParameter (key, Arrays.asList (valueArr)) / *** Error Line *** Return query.getResultList (); } In the above error line, it throws the following exception: java.lang.IllegalArgumentException: parameter value element [[Ljava.lang.String; @ cbe5bc] did not match the expected type [java.lang.String] Why is this expected type string while actually this string []? Please help! Note: This is derived from the normal routine and is a simplified code. I can no...
Read more

c++ - static template member variable has internal linkage but is not defined -

Yes, I know, there is a question with almost the same title, but it refers to a different situation. Error message) In my case, I have a .cpp file with a big named designation name (implementation details). There is a property class template with a static data member in that name space, which I need to access from outside the unknown namespace. I give it a little bit of meat: file.hpp namespace Bar {template & lt; Typename A & gt; Struct foo {static_assert (is_same & lt; a, float & gt; :: value} is_same & lt; a, double>: value, ""); Fixed zero set_static_var (a const & x); // ...}; } and file.cpp namespace {template & lt; Typename A & gt; Struct foo_traits {// supports the implementation of several static code bars: foo & lt; & Gt; Fixed A data; }; The template's & lt; & Gt; Float foo_traits & lt; Float & gt; :: datum; // No change if this is in the global namespace template & lt; & Gt; Doub...
Read more