for (statement 1 ; statement 2 ; statement 3){  
    code here...  
};  

function stringToBytes(val) { 
    const result = []; 
    for (let i = 0; i < val.length; i++) { 
        result.push(val.charCodeAt(i)); 
    } 
    return result; 
} 
  
const str1 = "Geeks"; 
const result = stringToBytes(str1); 
console.log(result);

[ 71, 101, 101, 107, 115 ]

Array.from(object, mapFunction, thisValue)  

let str1 = "Geeks"; 
let result = Array.from(str1, char => char.charCodeAt(0)); 
console.log(result);

[ 71, 101, 101, 107, 115 ]

let str = encoder.encode( str );  

const str1 = "Geeks"; 
const encoder = new TextEncoder(); 
const result = encoder.encode(str1); 
console.log(result);

Uint8Array(5) [ 71, 101, 101, 107, 115 ]