Question

What is the isdigit() equivalent in JavaScript

Answer 1

function isdigit(ch) {
    return ch >= '0' && ch <= '9';
}
 
const s = "c23c++45javascript23988rust98";
const size = s.length;
     
for (let i = 0; i < size; i++) {
     if (isdigit(s.charAt(i))) {
         console.log(s.charAt(i));
      }
}
 
 
 
 
 
 
/*
run:
 
"2"
"3"
"4"
"5"
"2"
"3"
"9"
"8"
"8"
"9"
"8"
 
*/

 

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Answer 2

function isdigit(ch) {
   return /^\d+$/.test(ch);
}

const s = "c23c++45javascript23988rust98";
const size = s.length;
    
for (let i = 0; i < size; i++) {
     if (isdigit(s.charAt(i))) {
         console.log(s.charAt(i));
      }
}






/*
run:

"2"
"3"
"4"
"5"
"2"
"3"
"9"
"8"
"8"
"9"
"8"

*/

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 3

function isdigit(ch) {
   return  !isNaN(parseFloat(ch));
}



const s = "c23c++45javascript203988rust98";
const size = s.length;
    
for (let i = 0; i < size; i++) {
     if (isdigit(s.charAt(i))) {
         console.log(s.charAt(i));
      }
}






/*
run:

"2"
"3"
"4"
"5"
"2"
"0"
"3"
"9"
"8"
"8"
"9"
"8"

*/

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile