JSFiddle - React, Tailwind, and code Playground

JavaScript

function fixedHex(number, length){
    var str = number.toString(16).toUpperCase();
    while(str.length < length)
        str = "0" + str;
    return str;
}

function unicodeLiteral(str){
    var i;
    var result = "";
    for( i = 0; i < str.length; ++i){
        if(str.charCodeAt(i) > 128)
            result += "\\u" + fixedHex(str.charCodeAt(i),4);
        else
            result += str[i];
    }
            
    return result;
}

var a = [
    ["a", 33],  
    ["h\u016B", 44],
    ["s\u00EF", 51]
];

var i;
for (i=0;i<a.length;i++) {
    document.write(unicodeLiteral(a[i][0]) + "<br />");
}