How to encode a string in JavaScript for displaying in HTML? [duplicate]

function htmlEntities(str) {
    return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
}

So then with var unsafestring = "<oohlook&atme>"; you would use htmlEntities(unsafestring);