单引号还是双引号

console.log("double"); vs console.log(‘single‘);

不应该以编码风格为重点，
而应该以引号内的内容为重点，
比如以下
alert(‘Say "Hello"‘);
alert("Say ‘Hello‘");

更复杂的
alert("It‘s \"game\" time.");
alert(‘It\‘s "game" time.‘);

ES6更喜欢用反斜杠

alert(`Use "double" and ‘single‘ quotes in the same string`);
alert(`The escape the \` back-tick character in a string`);

比如
`\`` === "`" // --> true
console.log("string text line 1\n"+
"string text line 2");
// "string text line 1
// string text line 2"