String

Strings are an immutable sequence of characters. String literals can be surrounded with double or single quotes.
    var a = "Hello World";  // double quotes
    var b = 'Hello World';  // single quotes

    // Strings have also a length property
    var n = b.length;       // n is now 11

    // Strings also have some built in methods
    n = b.index("Wor")      // n is now 6.

    n = b.count("l")        // n is now 3.
    n = b.count("llo")      // n is now 1.

    n = "A".repeat(10)      // n is now "AAAAAAAAAA"

    // upper() and lower() operate on the whole string when 0 arguments are passed
    n = b.upper()           // n is now "HELLO WORLD"
    n = b.lower()           // n is now "hello world"

    // upper() and lower() can both take multiple integer arguments
    n = b.upper(1, -1)     // n is now "HEllo WorlD"

    // split() is the opposite of a list join
    var string = "Roses are Red, Violets are Blue"
    var list = string.split(", ")
    list[0]                // "Roses are Red"
    list[1]                // "Violets are Blue"

    // Split can also be used to convert a string to a list type so that you can
    // call list specific methods
    var string = "abcdefghijklmnpqrstuvwxyz".split('')
    string.contains("o")   // false
    string.contains("s")   // true

    // You are also able to edit strings by character...
    b[0] = "Z"              // b is now "Zello World"
    b[1] = "abc"            // b is now "Zabco World"
    b[-7] = "QWERTY"        // b is now "ZabcQWERTYd"

    // and retrieve those characters
    n = a[6]                // n is now "W"
    n = a[-7]               // n is now "o"
    n = a[0...4]            // n is now "Hello"
    n = a[-5...-1]          // n is now "World"
    n = a[-5...10]          // n is now "World"
    n = a[-1...-5]          // n is now "dlroW"

    // replace o with i
    var str = "momo"
    str.replace("o", "i") // returns mimi