javascript - 从函数返回对象未按预期工作

Question

例如

function a(){
    return {
        testing:1
    };
}

function b(){
    return 
    {
        testing:1
    };
}

在上面的代码中，函数a()返回一个{testing:1}的对象，但函数b()返回值undefined。这种行为背后的原因是什么？

是不是因为返回值是从第二行开始的？

Answer 1

The return statement is affected by automatic semicolon insertion (ASI). No line terminator is allowed between the return keyword and the expression.

To avoid this problem (to prevent ASI), you could use parentheses:

return ( //return statement. );

function a(){
return ({
testing:1
});
}

function b(){
return( 
{
testing:1
});
}
console.log(a());
console.log(b());