cs - 234 exam 2 chpt9-fully solved

ECMAScript JavaScript is an implementation of this, not the same thing interpreter executes programming statements without first compiling the statements into machine language just-in-time(JIT) compilation Modern JavaScript interpreters use variable a named container that stores a value. Does not need to be declared before being assigned a value identifier a name created by a programmer for an item like a variable or function constant(const) an initialized variable whose value cannot change dynamic typing determines a variable's type at run-time comment any text intended for humans that is ignored by the javascript interpreter prompt() function that prompts the user with a dialog box that allows the user to type a single line of text and press OK or Cancel () output can be produced using this and it displays text or numbers console a location where text output is displayed syntax error the incorrect typing of a programming statement Compound assignment operator combines an assignment statement with an arithmetic operation string concatenation appends one string after the end of another string, forming a single string parseInt() and parseFloat() converts strings into numbers NaN means Not A Number isNaN() returns T if is not a number(1) and F if it is a number(0) Strict Equality (===) has to be completely identical meaning number to number and string to string non identity operator (!==) the opposite of strict equality truthy a non-boolean that evaluates to true in a boolean context falsey a non-boolean value that evaluates to false in a boolean context conditional operator(or ternary operator) if the condition evaluates to true, then the value of expression1 is returned, otherwise the value of expression2 is returned. i.e: condition ? expression1 : expression2