JAVASCRIPT MIDTERM EXAM QUESTIONS WITH VERIFIED SOLUTIONS GRADED A+
Keywords - Answers Terms in a programming language that are reserved for special purposes
by the programming language.
The three most common data types are: - Answers numbers, strings, boolean
Variables - Answers Program data is stored at locations in memory while a program is running.
The data value stored in a variable can then be used, and modified, by referencing its name.
Names can only contain - Answers letters, numbers, underscores, and dollar signs..
Names can only begin with - Answers a letter, underscore, or dollar sign. (generally, they always
start with a letter)
Can not have the same name as a - Answers JavaScript keyword
Spaces are - Answers not allowed in variable names
Variable names should be - Answers descriptive of the data they will
store.
Use camel case for variable names with - Answers multiple words in the name:
Operators - Answers Operators are used to modify or compare data.
An operator is simply a symbol or word that is used to evaluate data in a similar manner as
common math.
There are 6 types of operators - Answers Assignment Mathematical (Arithmetic) Comparison
Logical Bitwise Special
The Direct Assignment Operator (=) - Answers The Direct Assignment Operator (=)
Assignment operators are used to assign a value to a JavaScript variable.
Constants - Answers A constant is similar to a variable except that the value doesn't change
during program execution, it remains constant. A constant is just a variable in JavaScript.
Mathematical Operators - Answers The Mathematical operators are the symbols used to add,
subtract, multiply, and divide numbers in JavaScript.
Expressions - Answers Expressions evaluate to values
Any piece of code that produces a value is an expression
What is a program statement? - Answers It is an individual instruction for the computer to
process
, the if statement - Answers A selection control structure evaluates a condition, which is an
expression that's true or false. This allows the program to choose between different courses of
action.
Comparison Operators - Answers Comparison Operators evaluate two values as equal or
different (the same, less-than or greater-than). They operate the same way as relational
operators in math.
The while loop - Answers The repetition control structure, a loop, is a code block that is
executed one or more times
Comments - Answers // and /* */
The JavaScript Console. It allows developers to: - Answers Interactively execute JavaScript on a
command line.
○ Log JavaScript messages and output that are
not visible outside of the console.
○ Troubleshoot, test, and debug code.
○ It is not part of JavaScript. It is provided as
part of the JavaScript runtime environment. In our case, the browser.
Language Level: Low-Level - Answers Closest to machine language
Language Level: Lower Mid-Level - Answers Human readable but able to write at the machine
level if necessary - slightly more abstracted from the machine level.
Memory efficient Programmer still has to code mostly by hand
Language Level: Upper Mid-Level - Answers Human readable - Higher level of abstraction from
the machine level
Medium memory efficiency
Less manual coding of common features. More features are built-in, or easily added through pre
-built libraries of code
Language Level: High Level - Answers Human readable - Highest level of abstraction from the
machine. Least memory efficient level of programming languages.
Least amount of manual coding for common features. Many features are built-in, and/or easily
added through pre-built libraries of code
Keywords - Answers Terms in a programming language that are reserved for special purposes
by the programming language.
The three most common data types are: - Answers numbers, strings, boolean
Variables - Answers Program data is stored at locations in memory while a program is running.
The data value stored in a variable can then be used, and modified, by referencing its name.
Names can only contain - Answers letters, numbers, underscores, and dollar signs..
Names can only begin with - Answers a letter, underscore, or dollar sign. (generally, they always
start with a letter)
Can not have the same name as a - Answers JavaScript keyword
Spaces are - Answers not allowed in variable names
Variable names should be - Answers descriptive of the data they will
store.
Use camel case for variable names with - Answers multiple words in the name:
Operators - Answers Operators are used to modify or compare data.
An operator is simply a symbol or word that is used to evaluate data in a similar manner as
common math.
There are 6 types of operators - Answers Assignment Mathematical (Arithmetic) Comparison
Logical Bitwise Special
The Direct Assignment Operator (=) - Answers The Direct Assignment Operator (=)
Assignment operators are used to assign a value to a JavaScript variable.
Constants - Answers A constant is similar to a variable except that the value doesn't change
during program execution, it remains constant. A constant is just a variable in JavaScript.
Mathematical Operators - Answers The Mathematical operators are the symbols used to add,
subtract, multiply, and divide numbers in JavaScript.
Expressions - Answers Expressions evaluate to values
Any piece of code that produces a value is an expression
What is a program statement? - Answers It is an individual instruction for the computer to
process
, the if statement - Answers A selection control structure evaluates a condition, which is an
expression that's true or false. This allows the program to choose between different courses of
action.
Comparison Operators - Answers Comparison Operators evaluate two values as equal or
different (the same, less-than or greater-than). They operate the same way as relational
operators in math.
The while loop - Answers The repetition control structure, a loop, is a code block that is
executed one or more times
Comments - Answers // and /* */
The JavaScript Console. It allows developers to: - Answers Interactively execute JavaScript on a
command line.
○ Log JavaScript messages and output that are
not visible outside of the console.
○ Troubleshoot, test, and debug code.
○ It is not part of JavaScript. It is provided as
part of the JavaScript runtime environment. In our case, the browser.
Language Level: Low-Level - Answers Closest to machine language
Language Level: Lower Mid-Level - Answers Human readable but able to write at the machine
level if necessary - slightly more abstracted from the machine level.
Memory efficient Programmer still has to code mostly by hand
Language Level: Upper Mid-Level - Answers Human readable - Higher level of abstraction from
the machine level
Medium memory efficiency
Less manual coding of common features. More features are built-in, or easily added through pre
-built libraries of code
Language Level: High Level - Answers Human readable - Highest level of abstraction from the
machine. Least memory efficient level of programming languages.
Least amount of manual coding for common features. Many features are built-in, and/or easily
added through pre-built libraries of code
