String常见空指针避免技巧

1.比较equals

String name = getName();

if (name.equals("test")) {
System.out.println("hello");
}
如果name为空,
NullPointerException


----》推荐
String name = getName();

if ("test".equals(name)) {
System.out.println("hello");
}
equals如果name为空,直接返回false

2.转化为String
Object name = getName();
System.out.println(name.toString());
name为空会导致空指针
---推荐
Object name = getName();
System.out.println((String)name);
name为空会输出null



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转载自www.cnblogs.com/newcbs/p/12956007.html