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J a v a S cript

J a v a S cript. popo. J a v a S cript. JavaScript is a programming language used to make web pages interactive . JavaScript is scripting language used for client side scripting .  JavaScript developed by Netscape in 1995 Case sensitive. popo. JavaScript. Benefits of JavaScript

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J a v a S cript

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  1. JavaScript popo

  2. JavaScript • JavaScript is a programming language used to make web pages interactive. • JavaScript is scripting language used for client side scripting. •  JavaScript developed by Netscape in 1995 • Case sensitive popo

  3. JavaScript • Benefits of JavaScript • JavaScript gives HTML designers a programming tool • JavaScript can react to events Alert Messages • JavaScript can be used to validate data • JavaScript can be used to input Validation • Disadvantages of JavaScript • Depends on the browser popo

  4. JavaScript • Java and JavaScript • Java and JavaScript are two completely different • Java (developed by Sun Microsystems) is a powerful and much more complex programming. • JavaScript is scripting language used for client side scripting.  • JavaScript developed by Netscape in 1995. popo

  5. JavaScript • Embedding JavaScript in HTML • <script> tag is used to insert a JavaScript into an HTML page • <html> • <body> • <script language="javascript"> • document.write ("Hello"); • </script> • </body> • </html> popo

  6. JavaScript • External file • JavaScript can be put in a separate.jsfile <script src="myJavaScriptFile.js"></script> An external .jsfile lets you use the same JavaScript on multiple HTML pages popo

  7. JavaScript • <html> • <body> • <script language="javascript"> • document.write ("<p><b><i>Welcome to popo! Hello"); • </script> • </body> • </html> • document.write()- method used to print text popo

  8. JavaScript • document.writeln() and \n • - used to print in new line(only valid when <PRE> tag) •  (pre format) • <html> • <body> • <pre> • <script language="javascript"> • document.write ("<p><b><i>Welcome to popo! \nHello"); • document.writeln ("and peepe"); • </script> • </body> • </html> popo

  9. JavaScript • lastModified • include the last update date on your page by using the following code: • <script language="JavaScript"> • document.write("This page Last update:" + document.lastModified); • </script> popo

  10. JavaScript • bgColor and fgColor • <script> • document.bgColor="black“; • document.fgColor="#336699“; • </script> popo

  11. JavaScript • Data Types • Basic types of data in JavaScript are • strings, numbers, boolean and null. • String- group of characters enclosed in double quote • Number- integers and floating point values • Boolean- true or false • Null- represents nothing and has a special value, indicated by null popo

  12. JavaScript • Variables • Variables are storage locations used to store date • Variable can be declared as • var variable name= value; • Eg • Var example=“this is a string”; • <html> • <body> • <pre> • <script language="javascript"> • var name="popo"; • document.writeln ("My name " +name); • </script> • </body> • </html>

  13. JavaScript • Operators • JavaScript uses “operators” allows to make mathematical calculations • Assignment operators =, +=, -=, *=,/= • Arithmetic operators +, -, *, /, % • Logical operators &&, || , != • Comp`arison operators <, <=, >, >=, ==, != • Conditional operator (exp1)?(exp2) : (exp3); popo

  14. JavaScript • <html> • <body> • <pre> • <script language="javascript"> • var a=10; • var b=20; • varc=a+b; • document.writeln ("sum of "+a+" + "+b+" = "+ c); • </script> • </body> • </html> popo

  15. JavaScript • <html> • <body> • <pre> • <script language="javascript"> • var a=10; • var b=20; • var c=a+b; • if(c%2==0){document.write("even");} • else{document.write("odd");} • </script> • </body> • </html> popo

  16. JavaScript • loop statements:while (condition) statement; do statement while (condition); for (initialization; condition; increment) statement; • <html> • <body> • <pre> • <script language="javascript"> • vari; • for(i=1;i<=40;i++) • document.writeln(i); • </script> • </body> • </html> popo

  17. JavaScript • The switch statement: switch (expression) • { case label :statement; break; case label :statement; break; ... default : statement; } popo

  18. JavaScript • Alert() method • Used to alert the user on some action, with some information • Syn • alert(“message”); • <html> • <body> • <pre> • <script language="javascript"> • alert("I am popo"); • </script> • </body> • </html> popo

  19. JavaScript • Prompt() Method • Prompt method displays a small dialog box with a provision for text entry along with 2 buttons • Ok and Cancel • The text entered in the box can be stored in a variable • <html> • <body> • <pre> • <script language="javascript"> • var age= prompt("enter age"); • if(age>=20)alert("I am happy"); • else alert("I am popo"); • </script> • </body> • </html> • Can assign value var k=prompt("dfgsdf",“value"); popo

  20. JavaScript • Confirm() method • Enables the user to confirm • <html> • <body> • <pre> • <script language="javascript"> • var age=prompt("enter age"); • if( confirm("is it greater than 20") )alert("I am happy"); • else alert("I am popo"); • </script> • </body> • </html> popo

  21. JavaScript • parseInt()- convert string to integer • parseFloat()-convert string to float • var a= parseInt(b)+parseInt( c); • <html> • <body> • <pre> • <script language="javascript"> • var a="10"; • var b="20"; • var c=a+b; • alert(c); • var d=parseInt(a)+parseInt(b); • alert(d); • </script> • </body> • </html> popo

  22. JavaScript • eval() method • evaluate a numeric expression given as a string into numerical value • Eg • Eval(“10*10”); 100 popo

  23. JavaScript • Date function • Date manipulations can be performed by the method of the Date object • Create an instance of Date object • Using different methods of Date object user can carry out date manipulations • Some methods are

  24. JavaScript • Date methods popo

  25. JavaScript • <html> • <body> • <pre> • <script language="javascript"> • var d=new Date(); • document.write(d.getDate()+"/"+d.getMonth()+1 +"/"+d.getYear()); • </script> • </body> • </html> • Output -10/01/2013 popo

  26. JavaScript • Functions • Function can be defined • function function name(arguments) • { • Function body; • } • Eg • function fact(num) • { • var fact=1; • for(i=1;i<=num;i++) • fact=fact*i; • return fact; • } popo

  27. JavaScript • <HEAD> • <SCRIPT LANGUAGE="JavaScript"> • function square(number) • {alert( number * number);} • </SCRIPT> • </HEAD> • <BODY> • <SCRIPT> • document.write("The function returned ", square(5) ); • </SCRIPT> • </BODY> popo

  28. JavaScript • <HEAD> • <SCRIPT LANGUAGE="JavaScript"> • function square(number) • {return number * number;} • </SCRIPT> • </HEAD> • <BODY> • <SCRIPT> • document.write("The function returned ", square(5)); • </SCRIPT> • </BODY> • The function returned 25. popo

  29. JavaScript • Event handler • Event handlers can be considered as triggers that execute JavaScript when something happens, such as click or move your mouse over a link, submit a form etc. • Events are signals generated when specific action occur.Script can be written to react to these events. popo

  30. JavaScript popo

  31. JavaScript • onClick • onClick handlers execute only when users click on buttons, links, etc. • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <input type="button" value="Click here" onClick="ss()"> • </form> • The function ss() is invoked when the user clicks the button. • Note: Event handlers are not added inside the <script> tags popo

  32. JavaScript • onDblclick • Occurs when a mouse double-click • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <input type="text" value="10" onDblclick=" ss();"> • </form> popo

  33. JavaScript • onMousedown • Occurs when mouse button is pressed • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <input type="text" value="10" onMousedown=" ss();"> • </form> popo

  34. JavaScript • onMousemove • Occurs when mouse pointer moves • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <input type="text" value="10" onMousemove=" ss();"> • </form> popo

  35. JavaScript • onMouseout • Occurs when mouse pointer moves out of an element • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <table border=2 width=100 heigth=100 > • <tr><td bgcolor=brown onMouseout=" ss();"> • <font color=red >popo • </form> popo

  36. JavaScript • onkeypress • Occurs key is pressed and released • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form> • <input type="text" value="10" onkeypress=" ss();"> • </form> popo

  37. JavaScript • onsubmit • Occurs when a form is submitted • <script> • function ss() • { • alert("Thank you popo!") • } • </script> • <form onsubmit=" ss();"> • <input type="submit" value="dfsdfg" onSubmit=" ss();"> • </form> popo

  38. JavaScript • onload • Occurs when a page is loaded • <script> • function ss() • { • alert("popo"); • } • </script> • <body onLoad="ss()"> popo

  39. JavaScript • onmouseover • Occurs when mouse pointer moves over an element • <script> • function ss() • { • document.write("popo"); • } • </script> • <a href="#" onMouseover="ss();">Over Here!</a> popo

  40. JavaScript • unload • Occurs when user leaves a page • <body onUnload="alert('Thank you for visiting us. See you soon')"> popo

  41. JavaScript • Most of the events handlers are associated with the following object popo

  42. JavaScript • Addition of 2 nos (each Nos in 2 text, result in result text, with a button) • <script> • function calcu(f) • { • f.ans.value=parseInt(f.first.value)+parseInt(f.sec.value); • } • </script> • <form name=f> • Enter first no :<input type=text name=first> • <br> • Enter sec no:<input type=text name=sec> • <input type=button value=calculate onClick="calcu(f);"> • <br><br><br> • <input type=text name=ans> • </form> popo

  43. JavaScript • </script> • <form name=f> • Enter first no :<input type=text name=first> • <br> • Enter sec no:<input type=text name=sec><br> • <input type=button value=Add onClick="add(f);"> • <input type=button value=Sub onClick="sub(f);"> • <input type=button value=MultonClick="mult(f);"> • <input type=button value=Div onClick="div(f);"> • <br><br><br> • Answer :<input type=text name=ans> • </form> • All arithmetic operation with 4 buttons & 3 text • <script> • function add(f){ • f.ans.value=parseInt(f.first.value)+parseInt(f.sec.value); • } • function sub(f){ • f.ans.value=parseInt(f.first.value)-parseInt(f.sec.value); • } • function mult(f){ • f.ans.value=parseInt(f.first.value)*parseInt(f.sec.value); • } • function div(f){ • f.ans.value=parseInt(f.first.value)/parseInt(f.sec.value); • }

  44. JavaScript • Print First n nos • <script> • function pr(f) • { var n=parseInt(f.no.value); • for(i=1;i<=n;i++) • document.write(i+" &nbsp;&nbsp;"); • } • </script> • <form> • Enter limt no :<input type=text name=no> • <input type=button value=print onClick="pr(this.form);"> • </form> popo

  45. JavaScript

  46. JavaScript • String length • Varstr="Hello world!"document.write(str.length); • ------------------------------------------------------------------------ • <script> • function s(f) • { • st=f.st.value • alert(st.length); • } • </script> • <form name="feedback"> • Email:<input type="text" size="20" name="st" onblur="s(this.form)"> • </form> • </body></html> popo

  47. JavaScript • charAt() function to get character from a location inside a string • varmy_str="Welcome “document.write(my_str.charAt(3) ); • The output of above code is c . concat() join 2 strings • Var var2=" popo"var var3= " pp"varvar4=var1.concat(var2,var3);document.write(var4); popo

  48. JavaScript • indexOf() to get location of a string • varmy_str="popo and pp" • document.write( my_str.indexOf("and") ) ; • Output 5 . • lastIndexOf()This function returns the position of string by checking from end or right side of the string • varmy_str="popo and pp" • document.write( my_str.lastIndexOf("a") ) ; • Output 5 . popo

  49. JavaScript • Search & replace of part of string by replace() method • varmsg="Welcome to popo"; • msg=msg.replace("popo","Ajith"); • document.write(msg); • Output : Welcome to Ajith popo

  50. JavaScript • Substring() • In substr() function we used start point and length of the substring required • my_string= new String("Welcome to popo"); • document.write(my_string.substring(2,5)); • Output : lco popo

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