Soy un novato en Javascript. Entonces, perdónenme por cualquier error relacionado con la terminología. He creado una matriz dentro de un bucle for. Aquí está el código. Cada vez que uso la consola fuera de la condición y el bucle, solo se muestra una sola línea. Actualicé la pregunta y agregué la matriz. Quiero seleccionar la matriz que tiene arroz y verla fuera del bucle for.
Necesito ver esto cada vez que uso la consola fuera del ciclo: 
const datastructure= [ {"months":"January","productname":"Rice","production":"10","hector":"2"}, {"months":"February","productname":"Rice","production":"11","hector":"2"}, {"months":"March","productname":"Rice","production":"12","hector":"2"}, {"months":"April","productname":"Rice","production":"13","hector":"2"}, {"months":"January","productname":"Fruit","production":"14","hector":"2"}, {"months":"February","productname":"Fruit","production":"15","hector":"2"}, {"months":"Markch","productname":"Fruit","production":"16","hector":"2"}, {"months":"April","productname":"Fruit","production":"16","hector":"2"}, ]; for(i in datastructure){ if(datastructure[i].productname=="Rice") { var months=datastructure[i].months var productname=datastructure[i].productname var production=datastructure[i].production var hector=datastructure[i].hector formatedata =[({'months':months, 'productname':productname,'production':production,'hector':hector})]; console.log(formatedata) } }Creo que necesitas usar .filter en lugar de un bucle for
const datastructure= [ {"months":"January","productname":"Rice","production":"10","hector":"2"}, {"months":"February","productname":"Rice","production":"11","hector":"2"}, {"months":"March","productname":"Rice","production":"12","hector":"2"}, {"months":"April","productname":"Rice","production":"13","hector":"2"}, {"months":"January","productname":"Fruit","production":"14","hector":"2"}, {"months":"February","productname":"Fruit","production":"15","hector":"2"}, {"months":"Markch","productname":"Fruit","production":"16","hector":"2"}, {"months":"April","productname":"Fruit","production":"16","hector":"2"} ]; const riceProducts = datastructure.filter(({ productname }) => productname === 'Rice'); riceProducts.forEach(( product )=> console.log(product)); // or just // console.log(riceProducts) .as-console-wrapper { max-height: 100% !important; top: 0 }Tendrá que empujar a la matriz de datos formateados en lugar de reasignarlo