Difference between revisions of "Javascript"
Jump to navigation
Jump to search
(→An Example of a Web Page that asks the user for input and then produces some output) |
(→Code which times when user input is received, and uses fade-in of text and has different style colors and fonts for differnet divisions of the webpage) |
||
(2 intermediate revisions by the same user not shown) | |||
Line 42: | Line 42: | ||
</pre> | </pre> | ||
− | ==Code which times when user input is received, and uses fade-in of text== | + | ==Code which times when user input is received, and uses fade-in of text and has different style colors and fonts for differnet divisions of the webpage== |
− | < | + | <pre> |
<html lang="en"> | <html lang="en"> | ||
<head> | <head> | ||
Line 118: | Line 118: | ||
} //The curly bracket shows this is the end of the loop; | } //The curly bracket shows this is the end of the loop; | ||
− | outputDiv.innerHTML += "<br> | + | outputDiv.innerHTML += "<br>Yours truly, <br>                     John <br>" ; |
//Add some blank lines | //Add some blank lines | ||
Line 126: | Line 126: | ||
//Run the function above to print several times. | //Run the function above to print several times. | ||
new_line(div1); | new_line(div1); | ||
− | |||
− | |||
Line 141: | Line 139: | ||
showText(div2); // Fade-in effect for the second div | showText(div2); // Fade-in effect for the second div | ||
}, 3200); | }, 3200); | ||
− | |||
Line 152: | Line 149: | ||
</script> | </script> | ||
− | |||
</body> | </body> | ||
</html> | </html> | ||
+ | </pre> | ||
==What Javascript can't do== | ==What Javascript can't do== |
Latest revision as of 16:01, 6 September 2024
An Example of a Web Page that asks the user for input and then produces some output, and has different styles for different divisions of the output webpage
<h1>Printing "Happy Birthday, NAME INPUT" 8 Times</h1> <div id="output"></div> <!-- This is where we will display the output we create below --> <script> //Javascript has to go in a special script section. // Prompt the user for his name let name = prompt("What is your name?") ; //We will this variable later. let how_many=8; function new_line(){ // Select the output div let outputDiv = document.getElementById('output'); // Print Happy Birthday 8 times for (let i = 1; i <= how_many; i++) { outputDiv.innerHTML += "Happy Birthday, "+ name +"!<br>" ; } //The curly bracket shows this is the end of the loop; //Add some blank lines outputDiv.innerHTML += " <br><br><br><br><br>" ; } //The curcly bracket shows this is teh end of the function. //Run the function and print happy birthday 8 times. new_line(); // Prompt the user for a number of additional times to repeat happy birthday." how_many" is already declared, so no "let" is needed or allowed; how_many = prompt("How many times would you like to see that?") ; //Run the function again, after a .4 second delay. let timer = setTimeout(new_line, 400); </script>
Code which times when user input is received, and uses fade-in of text and has different style colors and fonts for differnet divisions of the webpage
<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <style> #first_div { font-size: 24px; color: #3498db; opacity: 0; /* Start hidden */ transition: opacity 2s ease-in; /* Fade-in effect */ } #second_div { font-size: 36px; font-family: "Brush Script MT", Brush Script Std, cursive; color: red; opacity: 0; /* Start hidden */ transition: opacity 2s ease-in; /* Fade-in effect */ } #third_div { font-size: 18px; color: green; opacity: 1; /* Start hidden */ transition: opacity 2s ease-in; /* Fade-in effect */ } </style> </head> <body> <div id="first_div"> </div> <div id="second_div"> </div> <div id="third_div"> </div> <script>//Javascript has to go in a special script section. //We will use these variables later. let how_many=8; let div1 = 'first_div' let div2 = "second_div" let div3 = "third_div" // Function to make text visible with fade-in effect function showText(Div_ID) { const textElement = document.getElementById(Div_ID); textElement.style.opacity = 1; // Set opacity to 1 to fade in } // Set a timeout to call the function after the delay of .1 seconds setTimeout(function() { showText(div1); }, 100); // Prompt the user for their name let name = prompt('Type in your name.') ; function new_line(Div_ID){ // Select the output div let outputDiv = document.getElementById(Div_ID); // Print 8 times for (let i = 1; i <= how_many; i++) { outputDiv.innerHTML += "Hello, "+ name +".<br>" ; } //The curly bracket shows this is the end of the loop; outputDiv.innerHTML += "<br>Yours truly, <br>                     John <br>" ; //Add some blank lines outputDiv.innerHTML += " <br><br>" ; } //The curly bracket shows this is teh end of the function. //Run the function above to print several times. new_line(div1); // Prompt the user for the number of additional times to repeat. setTimeout(function(){ how_many= prompt("How about some more? Pick a number" );}, 2750); //Run the function again for div2, after a delay. setTimeout(function(){ new_line(div2); // Run new_line for the second div showText(div2); // Fade-in effect for the second div }, 3200); function f1(){ let outputDiv = document.getElementById(div3); outputDiv.innerHTML += "That's all of them. But reload the page in your browser and we can do it again.<br>" ; } setTimeout(f1, 6000); </script> </body> </html>
What Javascript can't do
- Javascript can't get rid of the "This page says" heading of windows it opens. This is a security anti-phishing feature, so people will know the question is coming from the Web, not from their apps.
- Javascript can't put italics, boldface, color, etc. into prompt windows.