Following is a list of commonly used JavaScript commands. These commands may or may not have a corresponding jQuery method.

JavaScript: common commands

alert() displays the contents between the parentheses in a popup dialog box
document.write() writes the contents between the parentheses to the web page
.indexOf() returns the 1st index at which the specified element is found in an array
isNaN() returns true if the value being tested is NOT a number 
location.reload(); refreshes the document when placed in a function
.match() returns matches to a regular expression in a string
parseInt() will turn the value of a string variable into an integer
.pop() removes the last item from an array
.preventDefault(); will cancel the default event
prompt() creates a popup dialog box with a text box that returns what was typed into the text box for use in the program
.push() places the contents of the parentheses at the end of an array
.replace() searches for a match to a regular expresion and replace it with another string
return value return is often placed inside a function and returns the value stated
.search() returns the position of a matched string from another string
.shift() removes the first item from an array 
.splice()  adds or removes items from an array at a specified index number and for a specified number of items. 
.test() checks for a match between a regular expression and a specified string
.toLowerCase() returns the value in all lower case letters
.toUpperCase() returns the value in all upper case letters