Why my object save only last data

Question

I'm create two Object, struct_one and auxiliary struct_two for primary save a data.
After addet data with help ".push". Everything data from "struct_one[]" array, have a last the data.
Thank.

 struct_one =  {  comments:[{comment:String}]  };

 struct_two = {comment:String};



function taskElementWork(){



    this. createBlockSaveNew = function(){

             struct_two.comment = 1 + "RED";

                struct_one.comments.push(struct_two); 

                   console.log(struct_one.comments[1].comment); // = 1RED

             struct_two.comment = 2 + "RED";

                struct_one.comments.push(struct_two); 

                   console.log(struct_one.comments[2].comment); // = 2RED

             struct_two.comment = 3 + "RED";

                struct_one.comments.push(struct_two); 

                   console.log(struct_one.comments[3].comment); // = 3RED



        console.log( struct_one.comments[1].comment); // = 3RED   -> Why!  

   }

}



test = new taskElementWork();

test.createBlockSaveNew();

Recommended for you: Get network issues from WhatsUp Gold. Not end users.

Answer 1

You use the same object reference on pushing.

You could take a new object before assigning values and pushing, like

function taskElementWork() {
    var struct_two = { comment: '' };
    struct_two.comment = 1 + "RED";
    struct_one.comments.push(struct_two); 
    console.log(struct_one.comments[1].comment); // = 1RED

    struct_two = { comment: '' };
    struct_two.comment = 2 + "RED";
    struct_one.comments.push(struct_two); 
    console.log(struct_one.comments[2].comment); // = 2RED

    var struct_two = { comment: '' };
    struct_two.comment = 3 + "RED";
    struct_one.comments.push(struct_two); 
    console.log(struct_one.comments[3].comment); // = 3RED
}

A slighy better way, is to use a function for building the structure and take a parameter for the comment:

function taskElementWork() {
    function buildStructure(comment) {
        return { comment: comment };
    }

    struct_one.comments.push(buildStructure(1 + "RED")); 
    console.log(struct_one.comments[1].comment); // = 1RED

    struct_one.comments.push(buildStructure(2 + "RED")); 
    console.log(struct_one.comments[2].comment); // = 2RED

    struct_one.comments.push(buildStructure(2 + "RED")); 
    console.log(struct_one.comments[3].comment); // = 3RED
}

Why my object save only last data

Sign up