L4, Conditional statement, CSE 202 JavaScript
- 1. Course Code: CSE 202 Course Title: Computer Programming Lab Lecture 4: Conditional Statement Course Teacher: Saurav Barua (SB) Assistant Professor, Dept. of CE, DIU Phone: +88-01715334075 Email: [email protected]
- 2. Contents 2 parseInt() and parseFloat() methods If statement Else statement Else if statement Conditional statement . Worked out problems
- 3. Conditional statement 3 Conditional statements are used to perform different actions based on different conditions. In JavaScript we have the following conditional statements: Use if to specify a block of code to be executed, if a specified condition is true Use else to specify a block of code to be executed, if the same condition is false Use else if to specify a new condition to test, if the first condition is false Use switch to specify many alternative blocks of code to be executed
- 4. if statement 4 Syntax: if (condition) { // block of code to be executed if the condition is true } Use the if statement to specify a block of JavaScript code to be executed if a condition is true.
- 5. else statement 5 Syntax: if (condition) { // block of code to be executed if the condition is true } else { // block of code to be executed if the condition is false } Use the else statement to specify a block of code to be executed if the condition is false.
- 6. else if statement 6 Syntax: if (condition1) { // block of code to be executed if condition1 is true } else if (condition2) { // block of code to be executed if the condition1 is false and condition2 is true } else { // block of code to be executed if the condition1 is false and condition2 is false } Use the else if statement to specify a new condition if the first condition is false.
- 7. parseInt() and parseFloat() 7 The parseInt() function parses a string argument and returns an integer. The parseFloat() function parses a string argument and returns a floating point number.
- 8. Worked out example 8 Example 4: Program to take input from prompt and classify the input data through JS and display result in the browser. (Program to classify the input data for turbidity (NTU) of drinking water, where <=10 NTU is low turbid, 11-50 NTU moderately turbid, 51-100 is high turbid and >100 is very high turbid. Google drive link: https://drive.google.com/drive/folders/1e2L2EOjHrX7MSy4yPCsep4i2t0J1 FSkQ?usp=drive_link Git-hub link: https://github.com/sauravbarua02/turbidityIfElse
- 9. Interface 9
- 10. html codes 10 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial- scale=1.0"> <title>Water Quality for turbidity</title> <link rel="stylesheet" href="style.css"> </head> <body> <div class="container" id="container"> </div> <script src="app.js"></script> </body> </html>
- 11. css codes 11 body{ margin: 0px; background-color: rgba(40,184,83,0.6); } .container{ background-color: rgba(40,184,83,0.2); height: 300px; width: 300px; display: flex; flex-direction: column; margin: 20px auto; padding: 10px; justify-content: center; align-items: center; font-size: larger; box-shadow: 0 0 4px 1px rgba(0,0,0,0.6); border-radius: 10px; }
- 12. JS codes 12 const containerEl = document.getElementById("container"); let turbidity = parseInt(prompt("Enter turbidity of water sample in NTU:")); function check(){ if(turbidity<=10) result = "Low turbid"; else if(turbidity>10&&turbidity<=50) result = "Moderate turbid"; else if(turbidity>50&&turbidity<=100) result ="High turbid"; else result = "Very high turbid"; return result; } function display(check){ val = check(); containerEl.innerText = " The water sample is " +val; } display(check);
- 13. Class tasks 13 Task 4.1: Program to classify the input data for pH of drinking, where <6.5 is acidic and alkaline, 6.5-8.5 normal range and safe for drinking and >8.5 hard and alkaline. Task 4.2: Program to classify the input data for grain size (mm) of soil, where <0.002 is clay, 0.002-0.075 is silt, 0.075-0.42 is fine sand, 0.42-2.0 is medium sand, 2.0-4.75 is coarse sand and >4.75 is gravel. Task 4.3: Program to classify the input data for average speed (mph) of traffic stream, where >60 is LOS A, 57-60 is LOS B, 54-57 is LOS C, 46-54 is LOS D, 30-46 is LOS E and <30 is LOS F. Task 4.4: Program to classify the input data for column slenderness ratio, where <32 is short column, 32-120 is medium column and >120 is long column. Task 4.5: Program to classify the input data for Froude number of hydraulic jump, where <=1.0 is no jump, 1-1.7 is undulating jump, 1.7-2.5 is weak jump, 2.5-4.5 is oscillating jump, 4.5-9.0 is stable jump and >9.0 is strong jump.
- 14. End of the Lecture 14