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:
Last Updated :
12 Sep, 2019
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