before I didn"t ask clearly, my entanglement point is more convenient to judge how to be equal to two Integer objects, because the former needs to judge null,
.Integer a = null;
Integer b = new Integer(128);
System.out.print(Objects.equals(a,b));//null Integer caches numbers between-128and 127. if you are out of range, you can only new new objects .
is generally not recommended to use = , because two-class comparison is whether the object is the same address.
generally uses the equals () method, and equals compares the content.
use the equals (Object) method to compare objects.
:<br>"Integer-128~127int==false"
int = 128 int = 127==true
public static void main(String[] args) {
int a = 127;
Integer i = new Integer(127);
System.out.println(a == i);
int b = 128;
i = new Integer(128);
System.out.println(b == i);
}
for the question of whether the second Integer object is empty, refer to the implementation of Integer.equals to determine the null first, and then execute the judgment condition.
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