JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = {1:{user_id:1, first_name:"first_name1", last_name:"lastname1", email:"user1@test.com"}, 7:{user_id:7, first_name:"user2", last_name:"test2", email:""}, 72:{user_id:72, first_name:"testing343", last_name:"", email:""}, 246:{user_id:246, first_name:"aaa", last_name:"ssss", email:""}};




//loop into array
    var arr = [];
    for( var key in data ){
      if( data.hasOwnProperty( key ) ){
        arr.push( data[key] );
      }
    }
  
    //now, sort your array
    arr.sort( function(a,b) { 
      var nameA=a.first_name.toLowerCase(),
          nameB=b.first_name.toLowerCase();
    
      if (nameA < nameB){ 
        return -1; 
      } else if (nameA > nameB){ 
        return 1
      } else{ 
        return 0
      }
    });

console.log( arr );