_.before() function in underscore.js is used to call a particular function a particular number of times. It uses a count variable that keeps the track of number of times the function is called.
Syntax:
_.before(count, function)
Parameters:
- Count: It is the number of times a function is to be called.
- Function: It is the function that runs the count times.
Return: This function returns the count of the function call.
Note: Please Link the underscore CDN before using this code directly in the browser through the code.
Example 1:
<!DOCTYPE html>
<html>
<head>
<script src =
"https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js" >
</script>
</head>
<body>
<script>
let print=()=>{
console.log("geeks for geeks")
}
console.log(`Print function will only run 3 times`)
//the print function cannot run more than 3 times
count=_.before(4, print);
//calling count function more than 3 times
count();
count();
count();
count();
count();
count();
count();
</script>
</body>
</html>
Output:
Example 2:
It is clear from the example that if The button is clicked again and again then print function will not be working as it as already reached the count.
<!DOCTYPE html>
<html>
<head>
<script src =
"https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js" >
</script>
</head>
<body>
<button id="btn">button</button>
<script>
let print=()=>{
console.log("geeks for geeks")
}
//the print function cannot run more than 99 times
count=_.before(100, print);
//calling count function more than 99 times
let btn=document.querySelector("#btn");
let run=()=>{
console.log(`Print function will only run 99 times`)
for(let i=0; i<5000; i++){
count()
}
}
btn.addEventListener("click", run)
</script>
</body>
</html>
Output:
