Picking all the numbers present in a string in JavaScript

We are required to write a JavaScript function that takes in a string that contains some one-digit numbers in between and the function should return the sum of all the numbers present in the string.

Example

The code for this will be ?

const str = 'uyyudfgdfgf5jgdfj3hbj4hbj3jbb4bbjj3jb5bjjb5bj3';
const sumNum = str => {
    const strArr = str.split("");
    let res = 0;
    for(let i = 0; i < strArr.length; i++){
        if(+strArr[i]){
            res += +strArr[i];
        };
    };
    return res;
};
console.log(sumNum(str));

Output

The output in the console ?

35

How It Works

The function splits the string into individual characters, then checks each character. The unary plus operator (+) converts characters to numbers - it returns 0 for non-numeric characters (which is falsy) and the actual number for digits (which is truthy).

Alternative Method Using Regular Expressions

const str = 'abc7def2ghi9jkl1mn';
const sumWithRegex = str => {
    const numbers = str.match(/\d/g) || [];
    return numbers.reduce((sum, num) => sum + parseInt(num), 0);
};
console.log(sumWithRegex(str));

19

Comparison

Conclusion

Both methods effectively extract and sum digits from strings. The split method offers direct control, while regex provides cleaner, more readable code for pattern matching.