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JavaScript

// Data extracted from file
var data = "2|User2|15\r\n3|User1|13";

// Define columns in file
var columnKeys = ["ID", "Username", "Age"];

// Custome column validation
var columnValidation = {
    "ID": function (value) {
        if (isNaN(value)) return false;
        else return true;
    },
        "Username": function (value) {
        return true;
    },
        "Age": function (value) {
        return true;
    }
};

var ValidateColumns = function (data, keys, rules) {
    var rowSep = "\r\n";
    var colSep = "|";

    // Get rows
    var rows = data.split(rowSep);
    _.each(rows, function (row) {
        // Get columns
        var columns = row.split(colSep);

        // Validate columns
        _.each(columns, function (column) {
            if (rules[keys[columns.indexOf(column)]](column)) console.log("Column " + keys[columns.indexOf(column)] + ": Passed");
            else console.log("Column " + keys[columns.indexOf(column)] + ": Failed");
        });
    });
};

ValidateColumns(data, columnKeys, columnValidation);