在Javascript中计算转义字符串文字

var str = "This is a \"quoted\" string.";
console.log(str); // 输出：This is a "quoted" string.

var str2 = 'This is a \'quoted\' string.';
console.log(str2); // 输出：This is a 'quoted' string.

var str3 = "This is a \\backslash.";
console.log(str3); // 输出：This is a \backslash.

var str4 = "This is a\nnew line.";
console.log(str4); // 输出：This is a
                   // new line.

var str5 = "This is a\rcarriage return.";
console.log(str5); // 输出：This is a
                   // carriage return.

var str6 = "This is a\ttab.";
console.log(str6); // 输出：This is a    tab.