JSFiddle - React, Tailwind, and code Playground

JavaScript

var obj = [
{ Address1: "dd",Address2: 'qww',BankAccNo: 44,BankBranchCode: 44,BloodGrp: 'A+' },
{ Address1: "dd",Address2: 'qww',BankAccNo: 44,BankBranchCode: 44,BloodGrp: 'A+' }
];

obj = obj.map( function( item ){
for(var key in item){
     item[ key.toUpperCase() ] = item[key];
    delete item[key];
}
    return item;
})
console.log( obj );