VueJS csv Filereader

The reason why the console.log is not displaying anything is because FileReader.readAsText() is asynchronous. It completes after the console.log has executed.

You can typically deal with this by putting a watch on fileInput or throwing a local event using vm.$emit from the onload handler.

Here's another way

        onFileChange: function(e) {
            const file = e.target.files[0];
            const reader = new FileReader();
            reader.onload = e => console.log(e.target.result);
            reader.readAsText(file);
        },

Reference Creating a Vue.js File Reader Component Using the FileReader API