Jewels and Stones

LeetCode題目: 771. Jewels and Stones

My solution:

/**
 * @param {string} jewels
 * @param {string} stones
 * @return {number}
 */
let numJewelsInStones = (jewels, stones) => {
    let count = 0;
    for(let i=0; i<stones.length; i++) {
        if(jewels.includes(stones[i])) count++;
    }
    return count;
};