slide môn học HDJ bài 8 the core language objects in javascript

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The Core language Objects in JavaScript Session A Recap   Scripting Language – Scenarios Language JavaScript’s Elements     Core JavaScript Object Client-Side JavaScript Object Server-Side JavaScript Object JavaScript’s Tokens      Variables Data Types Operators (Arithmetic, Comparison, Logical, String, Evaluation) Expression Regular Expression Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 A Recap  Various message boxes     Function     Alert Confirm Prompt Pre-defined functions User-defined functions Return statement Display Information Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Objectives  Work on Core Language Objects  Use object Attributes and Methods Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Objects  The properties (variables) that define the object and the methods (functions) that work on the data are included in the object  For example, a car is an object The properties of the car are its make, model, and color They have some common methods like, go (), brake(), reverse() Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Properties and Methods  To access the properties of the object, we must specify the object name and the property: objectName.propertyName  To access the methods of an object, we must specify the object name and the required method: objectName.method () Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Example function Car(model, type) { this.model = “Toyota”; this.type = “for King Nothing”; } this.run = function() { document.write(“Brmm…”); } Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Using objects  When creating a Web page we can insert:  Browser objects  Built in script language objects (vary depending on the scripting language used)   HTML elements We can also create our own objects for use in the programs Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 Object Hierarchy Browser Objects Script Objects HTML Elements Web Page Programming with HTML,DHTML & JavaScript/Session 8/ of 16 The this statement  The this statement is more of an internal property  Its value indicates the current object It can have standard properties such as name, length and value applied accordingly Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 10 of 16 The for in statement  The for in statement is used to cycle through each property of an object or each element of an array  The syntax is: for (variable in object) { statements; } Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 11 of 16 The with statement  The with statement is used to execute a set of statements that have a specified object as the reference  The property is assigned to the object specified in the with statement  The syntax is: with (object) { statements; } Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 12 of 16 New Operator    The new operator is used to create a new instance of an object type The object type may be user-define or built-in objectName = new objectType (param1 [,param2] [,paramN]) where, objectName is the name of the new object instance ObjectType is a function that defined the type of the object For example, Array Param[1, 2, ] are the property values of the object Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 13 of 16 Eval function    The eval function is used to evaluate a string of code without reference to any specific object The string can be a JavaScript expression, statement, or a group of statements The expression can include variables and properties of an object var x = 5; var z = 10; document.write(eval(“x + z + 5”)); Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 14 of 16 String object    The string object is used to manipulate and work with strings of text We can extract substrings and convert text to upper- or lowercase characters in a program The general syntax is, stringName.propertyName or stringName.methodName Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 15 of 16 Creating String object  There are different methods of creating strings  Using the var statement and optionally assigning it to a value  Using an assignment operator (=) with a variable name  Using the string () constructor Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 16 of 16 String Object  Properties   length Methods        charAt(index) charCodeAt(index) fromCharCode(icode, icode, icode…) indexOf(findString, pos) lastIndexOf(findString, pos) Substring(start, end) toLowerCase(), toUpperCase Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 17 of 16 Math Object  The Math object has properties and methods that represent advanced mathematical calculations function doCalc(x) var a; a = Math.PI * x alert("The area with a radius of " a); } { * x; of a circle + x + “ is " + Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 18 of 16 Math Object  Properties   PI Methods       abs(number) ceil(number) floor(number) round(number) random() pow(number, exp) Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 19 of 16 Date object  The Date built-in object contains both date and time information  The Date object does not have any properties  It has a large number of methods for setting, getting, and manipulating dates Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 20 of 16 Date object  The Date object stores dates as the number of milliseconds since January 1, 1970, 00:00:00 DateObject = new Date(parameters) Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 21 of 16 Date Object   Properties Methods         getDate() getDay() getMonth() getFullYear() getHours() getMinutes getSeconds getMiliseconds setDate() setMonth() setFullYear() Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 22 of 16 Array Object  Properties   length Methods      concat() slice(start, end) join() sort() reverse() Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 23 of 16 Timers  One Shot Timer   setTimeout(“javaScript code”, delay) Timer that Fires at Regular Intervals   setInterval(“javaScript code”, interval) clearInterval(handler) Web Page Programming with HTML,DHTML & JavaScript/Session 8/ 24 of 16 [...]... creating strings  Using the var statement and optionally assigning it to a value  Using an assignment operator (=) with a variable name  Using the string () constructor Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 16 of 16 String Object  Properties   length Methods        charAt(index) charCodeAt(index) fromCharCode(icode, icode, icode…) indexOf(findString, pos) lastIndexOf(findString,... Programming with HTML,DHTML & JavaScript/ Session 8/ 14 of 16 String object    The string object is used to manipulate and work with strings of text We can extract substrings and convert text to upper- or lowercase characters in a program The general syntax is, stringName.propertyName or stringName.methodName Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 15 of 16 Creating String object  There... to the object specified in the with statement  The syntax is: with (object) { statements; } Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 12 of 16 New Operator    The new operator is used to create a new instance of an object type The object type may be user-define or built -in objectName = new objectType (param1 [,param2] [,paramN]) where, objectName is the name of the new object instance... that defined the type of the object For example, Array Param[1, 2, ] are the property values of the object Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 13 of 16 Eval function    The eval function is used to evaluate a string of code without reference to any specific object The string can be a JavaScript expression, statement, or a group of statements The expression can include.. .The for in statement  The for in statement is used to cycle through each property of an object or each element of an array  The syntax is: for (variable in object) { statements; } Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 11 of 16 The with statement  The with statement is used to execute a set of statements that have a specified object as the reference  The property... Page Programming with HTML,DHTML & JavaScript/ Session 8/ 22 of 16 Array Object  Properties   length Methods      concat() slice(start, end) join() sort() reverse() Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 23 of 16 Timers  One Shot Timer   setTimeout( javaScript code”, delay) Timer that Fires at Regular Intervals   setInterval( javaScript code”, interval) clearInterval(handler)... JavaScript/ Session 8/ 18 of 16 Math Object  Properties   PI Methods       abs(number) ceil(number) floor(number) round(number) random() pow(number, exp) Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 19 of 16 Date object  The Date built -in object contains both date and time information  The Date object does not have any properties  It has a large number of methods for setting, getting,... manipulating dates Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 20 of 16 Date object  The Date object stores dates as the number of milliseconds since January 1, 1970, 00:00:00 DateObject = new Date(parameters) Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 21 of 16 Date Object   Properties Methods         getDate() getDay() getMonth() getFullYear() getHours() getMinutes... lastIndexOf(findString, pos) Substring(start, end) toLowerCase(), toUpperCase Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 17 of 16 Math Object  The Math object has properties and methods that represent advanced mathematical calculations function doCalc(x) var a; a = Math.PI * x alert( "The area with a radius of " a); } { * x; of a circle + x + “ is " + Web Page Programming with HTML,DHTML & JavaScript/ Session...  One Shot Timer   setTimeout( javaScript code”, delay) Timer that Fires at Regular Intervals   setInterval( javaScript code”, interval) clearInterval(handler) Web Page Programming with HTML,DHTML & JavaScript/ Session 8/ 24 of 16
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