Please enable JavaScript.

Coggle requires JavaScript to display documents.

JS (Statements (JavaScript STATEMENTS are composed from (Operators…

- - - - JavaScript uses arithmetic operators ( + - * / ) to compute values
        
        Addition
        Subtraction
        Multiplication
        Division
        % Modulus (Remainder)
        ++ Increment
        -- Decrement
      - JavaScript uses an assignment operator ( = ) to assign values to variables
        
        = || x = y || x = y
        += || x += y || x = x + y
        -= || x -= y || x = x - y
        = || x = y || x = x * y
        /= || x /= y || x = x / y
        %= || x %= y || x = x % y
      - JavaScript Comparison Operators
        
        == equal to
        === equal value and equal type
        != not equal
        !== not equal value or not equal type
        greater than
        < less than
        = greater than or equal to
        <= less than or equal to
        ? ternary operator
      - JavaScript Logical Operators
        
        && logical and
        || logical or
        ! logical not
      - JavaScript Type Operators
        
        typeof Returns the type of a variable
        instanceof Returns true if an object is an instance of an object type
    - - An expression is a combination of values, variables, and operators, which computes to a value.
    - - break Terminates a switch or a loop
        continue Jumps out of a loop and starts at the top
        debugger Stops the execution of JavaScript, and calls (if available) the debugging function
        do ... while Executes a block of statements, and repeats the block, while a condition is true
        for Marks a block of statements to be executed, as long as a condition is true
        function Declares a function
        if ... else Marks a block of statements to be executed, depending on a condition
        return Exits a function
        switch Marks a block of statements to be executed, depending on different cases
        try ... catch Implements error handling to a block of statements
        var Declares a variable
    - - Code after double slashes // or between / and / is treated as a comment.
    - - Variable values are called variables.
      - Fixed values are called literals
  - - - to specify a block of JavaScript code to be executed if a condition is true
    - - Use the else statement to specify a block of code to be executed if the condition is false.
    - - Use the else if statement to specify a new condition if the first condition is false.
    - - Use the switch statement to select one of many blocks of code to be executed.
- - - - An array represents an ordered
        collection of numbered values.
        
        Array Methods
        
        toString() converts an array to a string of (comma separated) array values
        
        The join() method also joins all array elements into a string.
        It behaves just like toString(), but in addition you can specify the separator
        
        The pop() method removes the last element from an array
        
        The push() method adds a new element to an array (at the end)
        
        The shift() method removes the first array element and "shifts" all other elements to a lower index.
        
        Since JavaScript arrays are objects, elements can be deleted by using the JavaScript operator delete
        
        The splice() method can be used to add new items to an array. The first parameter (2) defines the position where new elements should be added (spliced in).
        The second parameter (0) defines how many elements should be removed.
        
        The concat() method creates a new array by merging (concatenating) existing arrays
        
        The *slice()* method slices out a piece of an array into a new array.
        
        Sorting Arrays
        
        The reverse() method reverses the elements in an array.
        
        Math.max.apply finds the highest number in an array
        
        The sort() method sorts an array alphabetically
      - An object (that is, a member of the type object) is a collection of properties
        where each property has a name and a value (either a primitive value, such as a number
        or string, or an object).
    - - numbers
        
        toString() returns a number as a string
        
        toExponential() returns a string, with a number rounded and written using exponential notation.
        
        toFixed() returns a string, with the number written with a specified number of decimals
        
        toPrecision() returns a string, with a number written with a specified length
        
        valueOf() returns a number as a number
        
        Global Methods
        
        Number() can be used to convert JavaScript variables to numbers
        
        parseInt() parses a string and returns a whole number. Spaces are allowed. Only the first number is returned
        
        parseFloat() parses a string and returns a number. Spaces are allowed. Only the first number is returned
        
        Math Object
        
        Math.round(x) returns the value of x rounded to its nearest integer
        
        Math.pow(x, y) returns the value of x to the power of y
        
        Math.sqrt(x) returns the square root of x
        
        Math.abs(x) returns the absolute (positive) value of x
        
        Math.min() and Math.max() can be used to find the lowest or highest value in a list of arguments
        
        Math.random() returns a random number between 0 (inclusive), and 1 (exclusive)
      - strings of text (known as strings)
        
        String Methods
        
        The length property returns the length of a string.
        
        Finding a String in a String
        
        The lastIndexOf() method returns the index of the last occurrence of a specified text in a string
        
        The indexOf() method returns the index of (the position of) the first occurrence of a specified text in a string
        
        Searching for a String in a String
        
        The search() method searches a string for a specified value and returns the position of the match.
        
        Extracting String Parts
        
        slice() extracts a part of a string and returns the extracted part in a new string.
        The method takes 2 parameters: the starting index (position), and the ending index (position).
        
        substring() is similar to slice().
        The difference is that substring() cannot accept negative indexes.
        
        substr() is similar to slice().
        The difference is that the second parameter specifies the length of the extracted part.
        
        Replacing String Content
        
        The replace() method replaces a specified value with another value in a string
        
        Converting to Upper and Lower Case
        
        toUpperCase()
        
        toLowerCase()
        
        Extracting String Characters
        
        The charAt() method returns the character at a specified index (position) in a string
        
        The charCodeAt() method returns the unicode of the character at a specified index in a string
        
        Converting a String to an Array
        
        A string can be converted to an array with the split(separator(",": "|", " ")) method.
      - Boolean truth values
        (known as booleans).
        
        Boolean()
- - - - In HTML, the global scope is the window object. All global variables belong to the window object.
    - - The lifetime of a JavaScript variable starts when it is declared.
        Local variables are deleted when the function is completed.
        In a web browser, global variables are deleted when you close the browser window (or tab), but remain available to new pages loaded into the same window.
    - - Local variables have local scope: They can only be accessed within the function.