var search = init(
"id,first,last,emailn" +
"555,John,Doe,jd@gmail.comn" +
"666,Jason,scott,js@gmail.comn",
"email");

search("js@gmail.com"); /// -> {"id":"666","first":"Jason","last":"scott", "email":"js@gmail.com"}

function init(text, key) {
var arr = text.split('n'); /// convert text to array
var keyIndex = arr[0].split(',').indexOf(key); /// returns 3

return function(value) {
for (var i = 1; i < arr.length; i++) {
var dataLine = arr[i].split(','); /// "666,Jason,scott,js@gmail.comn" to array
if (dataLine[keyIndex] === value) { /// found match between value and id
return convertToObject(arr[0].split(','), dataLine);
}
}
return "not found";
}
}



function convertToObject(indexLine, dataLine) {
/// creates an object from 2 lines: {email: "js@gmail.com",first: "Jason", id: "666", last: "scott"}
var obj = {};
var result = "";
for (var j = 0; j < dataLine.length; j++) {
obj[indexLine[j]] = dataLine[j];
}
return JSON.stringify(obj); /// String format;
}