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How do you create a multi-line comment in JavaScript?
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Date created
Mar 1, 2020
Cards (103)
Section 1
(50 cards)
How do you create a multi-line comment in JavaScript?
Start with a forward slash and asterisk, and then end with an asterisk and forward slash. "/" "/"
What method allows you to set the digit precision of a decimal number?
toFixed(digitCount);
How do you test that a variable contains a valid number?
isNaN(varHere); //Returns true or false.
For textboxes, How do you set the control to be disabled?
document.getElementById("TextBoxId").disabled = true; //Could also be false to enable it
How do you create a function that returns a value in JavaScript?
var functionName = function(param1, param2, paramN) { //Other steps return returnValue; }
What values can confirm() return?
True or false
For radio buttons, how do you get the text value of the control?
document.getElementById("radioButtonId").value;
How do you denote a string in JavaScript
With either single or double quotes surrounding the data
For textboxes, how do you set focus on the control?
document.getElementById("TextBoxId").focus;
How do you create an Array object in JavaScript?
var arrayVar = new Array();
How do you view the current web address using JavaScript?
window.location();
How do you code an If Else If statement in JavaScript?
if (condition) { } else if (condition) {}
What is the string escape sequence to start a new line in JavaScript?
How do you access a page element by id?
document.getElementById(id);
How do you code an If Else statement in JavaScript?
if (condition){ } else {}
How do you display a confirmation?
confirm("Message Text Here");
What are the valid characters for an identifier in JavaScript?
Letters, Numbers, Underscores, and Dollar Signs
For textboxes, How do you get the current value?
document.getElementById("TextBoxId").value;
How do you assign the return value of confirm() to a variable?
var answerVar = confirm("Message Text Here");
How do you assign actions to the window onLoad event?
window.onload = function() {//actions here}
How do you assign the value from a prompt to a string?
var stringVar = prompt("Text Here");
For radio buttons, how do you get the current checked status of the control?
document.getElementById("radioButtonId").checked;
How do you code a while statement in JavaScript?
while (condition) {}
How do you display an alert?
alert("Alert Text Here");
How do you assign a default value to a prompt?
Using the second parameter. Example: prompt("Enter Age:", "18");
How do you code a for statement in JavaScript?
for (counter; condition; incrementor) {}
How do you assign the value from a prompt to a non-string variable?
Using a parse. Example : var intVar = parseInt(prompt("Text Here"));
How do you create a function in JavaScript?
var functionName = function(param1, param2, paramN) {}
What is an event handler?
A function that is called with a certain event occurs. Examples of these include button.onclick and window.onload.
Is JavaScript case sensitive?
Yes
For checkboxes, how do you get the text value of the control?
document.getElementById("checkboxId").value;
What is the command to display a prompt?
prompt("Text Here");
How do you write a line to the current element of the DOM?
document.writeln("Text Here"); //Advances to new line after text
In the <script> tag, how is the Defer attribute used?
<script defer="defer"> //Used to ensure the code doesn't run until the rest of the page has been loaded
How do you create a Date object in JavaScript?
var dateVar = new Date();
In the <script> tag, how is the Src attribute used?
<script src="fileName.js"> //Used to denote external file for script use
What are the four attributes of the <script> tag?
Type, Src, Charset, and Defer
For checkboxes, how do you get the current checked status of the control?
document.getElementById("checkboxId").checked;
What is AJAX?
Asynchronous JavaScript And XML
In the <script> tag, how is the Type attribute used?
<script type="text/javascript"> //Used to denote the type of script being used. Always this for JavaScript
How do you declare a variable in JavaScript?
var variableName;
How do statements end in JavaScript?
With a semicolon ";"
What is the <noscript> tag used for?
The text between the opening and closing tag is displayed if JavaScript is disabled or otherwise not available
For lists, how do you get the value or the currently selected item?
document.getElementById("listId").value;
How do you create a single line comment in JavaScript?
With two forward slashes "//"
How do you write text to the current element of the DOM?
document.write("Text Here"); //Remains on current line
What is the DOM?
Document Object Model
How do you make the browser load a new page using JavaScript?
window.location = "New Web Address Here";
How do you code an If statement in JavaScript?
if (condition) {}
How do you code a button.onclick event handler?
document.getElementById("ButtonId").onclick = functionName;
Section 2
(50 cards)
What Date object method is used to return the number of milliseconds since the start of GMT?
getTime();
How do you alter the value of the text element in a span tag?
document.getElementById("spanId").firstChild.nodeValue = "New Value";
For a text area, how do you set the current value of the control?
document.getElementById("textAreaId").value = "Text Value";
What Math object method is used to return the absolute value of a given number?
Math.abs(number);
What String object method is used return the position of the first instance of a specified search string, starting from the specified index?
indexOf(searchValue, startPosition); //If no startPosition is specified, the search begins from the start of the string
What makes the identity operators different from the standard equality operators?
They do not perform type coercion. //Eg. If data types don't match they fail the comparison
What Math object method is used to return a given number that has been rounded to the closes integer value?
Math.round(number);
What are the available set methods for a Date object?
setFullYear(); //Sets 4 digit year setMonth(); //Sets months, starts with 0 for January setDate(); // Sets day of the month setHours(); //Sets hours in the day setMinutes(); //Sets the minutes in the current hour setSeconds(); //Sets seconds in the current minute setMilliseconds(); //Sets milliseconds in the current second
How do you access the text element in a <span> tag?
document.getElementById("spanId").firstChild;
What Date object method is used to return a string containing the date and time?
toString();
What are the 3 shortcuts for Number object properties?
Infinity //Represents Number.POSITIVE_INFINITY -Infinity //Represents Number.NEGATIVE_INFINITY NaN //Represents Number.NaN
What is the format to create a new Date object from a string?
var dateObject = new Date("11/22/2012 18:25:35");
What String object method returns a new string containing the value of the original string but in all upper case?
toUpperCase();
What String object method is used to return a new string that contains part of the original string from the specified start position and up to but not including the specified stop index?
substring(startIndex, stopIndex); //stopIndex is optional, if it is not specified, then it will go until the end of the string
For radio buttons, how do you set the current checked status of the control?
document.getElementById("radioButtonId").checked = true; //Could also be false
What String object method is used to get the character at a specified index position?
charAt(position);
What Math object method is used to return a given number rounded to the next highest integer value?
Math.ceil(number);
What Number object method is used to return a string with a given number base?
toString(base); //Bases can range from 2 to 36
For checkboxes, how do you set the current checked status of the control?
document.getElementById("CheckboxId").checked = true; //Could also be false
What Math object method is used to return the square root of a given number?
Math.sqrt(number);
For a text area, how do you get the current character count for the control?
var areaText = document.getElementById("textAreaId").value; var charCount = areaText.length;
What Math object method is used to return the highest value from a set of supplied numbers?
Math.max(var1, var2, varN);
What is the string escape sequence to insert a backslash in JavaScript?
\\
What String object method is used to return a new string that contains part of the original string from the specified start position?
substring(startIndex);
What Math object method is used to return a given number rounded to the next lowest integer value?
Math.floor(number);
What Math object method is used to return the lowest value for a set of supplied numbers?
Math.min(var1, var2, varN);
What String object method returns a new string containing the value of the original string but in all lower case?
toLowerCase();
What is the string escape sequence to insert a tab in JavaScript?
\t
What String object method is used to concatenate multiple strings?
concat(var1, var2, varN);
What is the string escape sequence to insert a carriage return in JavaScript?
\r
How do you create a new Date object?
var dateObject = new Date(year, month, day, hours, minutes, seconds, milliseconds);
What are the available properties for the Number object?
Number.MAX_VALUE Number.MIN_VALUE Number.POSITIVE_INFINITY Number.NEGATIVE_INFINITY Number.NaN
What are the available get methods for a Date object?
getTime(); getFullYear(); //Returns 4 digit year getMonth(); //Returns months, starts with 0 for January getDate(); // Returns day of the month getHours(); //Returns hours in the day getMinutes(); //Returns the minutes in the current hour getSeconds(); //Returns seconds in the current minute getMilliseconds(); //Returns milliseconds in the current second
What Number object method is used to return a number in exponential format with the specified number of decimal places?
toExponential(digits);
What are the events common to most controls?
onfocus //Fired when control receives focus onblur //Fired when control loses focus onclick //Fired when the control is clicked ondblclick //Fired when the control is double clicked onchange //Fired when the control's value is changed onselect //Fired when text is selected in a textbox or text area
What is the string escape sequence to insert a form feed in JavaScript?
\f
What Date object method is used to return a string containing the date?
toDateString();
What is the string escape sequence to insert a single quote in JavaScript?
\'
What Date object method is used to return a string containing the time?
toTimeString();
What is the escape sequence used to insert a Unicode character into a string in JavaScript?
\udddd //"dddd" is replaced by the hexadecimal value for the Unicode character
What Number object method is used to round numbers to the specified number of decimal places?
toFixed(digits);
What is the string escape sequence to insert a double quote in JavaScript?
\"
What Math object method is used to return a given number raised to a given power?
Math.pow(number, power);
What is the syntax of a conditional operator?
(Condition_Expression) ? Value_If_True : Value_If_False;
For a text area, how do you get the current value of the control?
document.getElementById("textAreaId").value;
What is the string escape sequence to insert a vertical tab in JavaScript?
\v
What Number object method is used to return a numerical string with the specified number of significant digits?
toPrecision(precision);
What are the two methods common to most controls?
focus //Brings focus to the control blur //Removes focus from the control
How do you concatenate multiple parts into a string?
var stringVar = "part 1:" + "part 2";
What Math object method is used to return a random number?
Math.random() //Returns a value >= 0.0 but <1.0
Section 3
(3 cards)