字符串等于和==，带有字符串串联

当你做

System.out.println("Object and literal compare by double equal to :: " + s1 == s2);

您首先将字符串

"Object and literal compare by double equal to :: "

s1

"Object and literal compare by double equal to :: jai"

然后，您要检查此字符串是否是与以下对象相同的对象（相同的引用）

s2

"Object and literal compare by double equal to :: jai" == "jai"

将会是

false

false

换句话说，这是因为 运算符Priority 。一种“操纵”运算符优先级的方法是使用括号。括号内的运算将首先被解析：

System.out.println("Object and literal compare by double equal to :: " + (s1 == s2));