Comenzando en LearnStreet

He estado tomando el curso de javascript en https://www.learnstreet.com y me ha parecido bastante bueno. Es un poco parecido al de http://www.codecademy.com/ aunque tiene un nivel más alto y está mejor explicado. 

El entorno de trabajo es muy parecido al de codecademy pero más completo. 

Las explicaciones aparecen en el mismo entorno de trabajo. En codecademy aparecen del lado izquierdo. Aquí la sección del lado izquierdo está más completa y en el Overview se puede desplegar la teoría.

Aquí les pongo el Overview de la sección 3 correspondiente a STRINGS en javasceript:

Lesson 3: Dive into Strings

What is a String?

A string is a sequence of characters, such as letters, numbers, or other symbols. They are useful for storing text, website URLs, values for form fields, and more. To create a string in JS, surround the sequence of characters using single or double quotes. Note that if you start with a double quote, you must end it with a double quote. Likewise if using single quotes. The reason JS allows either to be used is that you can easily define strings that contain single or double quotes. For example, "i'm a string" uses double quotes so the single quote can be used as an apostrophe. If you need to define strings that contain both single and double quotes, you will need to escape them using the \ escape character, like 'Joe says "I\'m OK"'.

String Properties

The length of a string is the number of characters it has. You can find out the length of any string in JS by using the length property. It is one of the very few properties of JS strings. To access it, use the member (aka dot) . operator on the string, like"LearnStreet".length.

String Methods

JS strings come with many pre-defined methods. Methods are functions that belong to objects (both functions and objects will be covered in later sections. Also, don't worry too much about which terminology to use -- function vs. method, as the distinction isn't usually important). So string methods are methods that you can use on any string, using the member (dot) . operator, like "the string".toUpperCase(). Notice the parentheses after the method name. It is used to indicate that you are "calling" (running) the function. If the function takes inputs, you can pass them to the function by placing them inside the parentheses. If the function accepts more than one input, you separate the inputs by using a comma (and a space for readability). In the code "the string".substring(0, 3), the 0 and 3 are arguments (values passed to functions) for thesubstring method. Note that these examples use "the string" as the sample string. If we store that string in a variable using var myString = "the string";, we can call the toUpperCase on the variable using myString.toUpperCase() instead.

Before getting into some of the pre-defined string methods, let's discuss indices first. You can think of string indices as positions of the characters, except they are 0-based in JS. Meaning the first character starts at index 0, and the last character is at index of length - 1. For example, in the string "Moon", 'M' is at index 0, the two 'o's are at indices 1 and 2, and 'n' is at index 3.

Here are some common string functions JS provide:

• charAt(index) gets the character at the given index. 
  
  
  Example: "LearnStreet".charAt(0); returns 'L' and"LearnStreet".charAt(5); returns 'S'.

• substring(start, end) gets the string starting at the startindex and going up to but not including the end index. If theend parameter is left out, it will return a string starting at thestart index and going to the end of the string. 
  
  
  Example: "LearnStreet".substring(0, 5); returns "Learn" and"LearnStreet".substring(5); returns "Street".

• indexOf(value) returns the the first index of the specified character or string. 
  
  
  Example: "LearnStreet".indexOf("e"); returns 1 because the letter 'e' first occurs at index 1.

• toUpperCase() changes all letters in the string to uppercase. 
  
  
  Example: "LearnStreet".toUpperCase(); returns "LEARNSTREET".

---------------------------------------

Como ven está bastante completo el sitio. Me ha dejado con gran sabor de boca. Igual que en otras escuelas de programación online uno va ganando insignias y puede compartir en redes sociales sus avances. 

El último tip viene al final del overview arriba mencionado y es que Mozilla tiene una lista completa de STRING METHODS que conviene ver. El link es el siguiente:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/prototype#Methods

Es todo por hoy; mañana continuaremos.

Buen código.