How to generate a random boolean using JavaScript ?
The task is to generate random boolean value. Here we are going to use JavaScript to achieve the goal.
Approach 1:
- Calculate Math.random() function.
- If it is less than 0.5, then true otherwise false.
Example 1: This example implements the above approach.
<!DOCTYPE HTML> <html> <head> <title> How to generate a random boolean using JavaScript? </title></head> <body style = "text-align:center;" id = "body"> <h1 id = "h1" style = "color:green;" > GeeksForGeeks </h1> <p id = "GFG_UP" style = "font-size: 15px; font-weight: bold;"> </p> <button onclick = "gfg_Run()"> Click here </button> <p id = "GFG_DOWN" style = "font-size: 23px; font-weight: bold; color: green; "> </p> <script> var el_up = document.getElementById("GFG_UP"); var el_down = document.getElementById("GFG_DOWN"); el_up.innerHTML = "Click on the button to " + "generate random boolean."; function gfg_Run() { el_down.innerHTML = Math.random() >= 0.5; } </script> </body> </html> |
Output:
- Before clicking on the button:
- After clicking on the button:
Approach 2:
- Create an array containing ‘true’ and ‘false’ values.
- Calculate Math.random() and round its value.
- Use rounded value as the index to the array, to get boolean.
Example 2: This example implements the above approach.
<!DOCTYPE HTML> <html> <head> <title> How to generate a random boolean using JavaScript? </title></head> <body style = "text-align:center;" id = "body"> <h1 id = "h1" style = "color:green;" > GeeksForGeeks </h1> <p id = "GFG_UP" style = "font-size: 15px; font-weight: bold;"> </p> <button onclick = "gfg_Run()"> Click here </button> <p id = "GFG_DOWN" style = "font-size: 23px; font-weight: bold; color: green; "> </p> <script> var el_up = document.getElementById("GFG_UP"); var el_down = document.getElementById("GFG_DOWN"); var ar = [true, false]; el_up.innerHTML = "Click on the button to " + "generate random boolean."; function gfg_Run() { var index = Math.round(Math.random()); el_down.innerHTML = ar[index]; } </script> </body> </html> |
Output:
- Before clicking on the button:
- After clicking on the button:
