オブジェクトをJSON文字列（UNICODE）に変換する

var obj = {"key":"ü"}; var str1 = JSON.stringify(obj); var str2 = ""; var chr = ""; for(var i = 0; i < str1.length; i++){ if (str1[i].match(/[^\x00-\x7F]/)){ chr = "\\u" + ("000" + str1[i].charCodeAt(0).toString(16)).substr(-4); }else{ chr = str1[i]; } str2 = str2 + chr; } console.log(str2); >>{"key":"\u00fc"}

javascript - JSON.stringify and unicode characters - Stack Overflow