 <pre><code>var Book = {"Titles":[ { "Book3" : "BULLETIN 3" } , { "Book1" : "BULLETIN 1" } , { "Book2" : "BULLETIN 2" } ]} var findbystr = function(str) { var return_val; Book.Titles.forEach(function(data){ if(typeof data[str] != 'undefined') { return_val = data[str]; } }, str) return return_val; } book = findbystr('Book1'); console.log(book); </code></pre>