1 / 6

Lecture 4: Javascript Basics

Lecture 4: Javascript Basics. Javascript is a scripting language based on pieces of C, C++, shell scripts, Pascal, Java, etc. Scripts – loosely typed C++ - object oriented ideas Pascal – some syntax elements C – much program syntax and semantics Java – no pointers

merrill-peterson
Download Presentation

Lecture 4: Javascript Basics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 4: Javascript Basics Javascript is a scripting language based on pieces of C, C++, shell scripts, Pascal, Java, etc. Scripts – loosely typed C++ - object oriented ideas Pascal – some syntax elements C – much program syntax and semantics Java – no pointers Check this example out…. Program

  2. Example source code <html> <head> <title>testing javascript</title> <body> <P><h1>This is a Javascript example. It adds two numbers and then pr</h1> </p> <script language = "Javascript"> var i=1 ; while( i < 1000000) i+=1; window.alert("Fatal system error. Restart your computer now?"); </script> </body> </html>

  3. Javascript basics Declaring variables: var keyword, typeless variables Basic I/O: document.writeln( ); window.alert( ); window.prompt( ); Type conversion: parseInt( );

  4. Another example <html> <head> <title>testing1.html</title> <body> <script language = "Javascript"> var number1, n1,n2, number2, sum; number1=window.prompt("enter number 1", "0"); number2=window.prompt("enter number 2", "0"); n1 = parseInt(number1); n2= parseInt(number2); sum = n1 + n2; document.writeln("<P>Sum is "+sum+"</P>"); </script> </body> </html>

  5. Control structures Boolean expressions for loops while statements if then else switch statements

  6. Another example <html> <head> <title>testing1.html</title> <body> <script language = "Javascript"> var n1,n2,counter=0,i, piest = 0, // quadrant =new Array(4); sum=0; counter=window.prompt("Enter the number of desired samples:","100"); counter=parseInt(counter); for (i=1 ; i<=counter ; ++i) { n1=(Math.random()-0.5)*2; n2=(Math.random()-0.5)*2; if ((n1*n1)+(n2*n2) < 1) piest +=1; }; sum=(4*piest/counter); document.writeln("The estimate of pi is "+sum); </script> </body> </html>

More Related