finally一定会执行return以最后一次为准return后的finally是否修改了数据，得看具体类型
try{} catch(){}finally{} return
按照正常的顺序执行：有错会执行catch，finally都会执行，最后执行return。
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| private static int returnInFinally_00(){
int a ;
try {
System.out.println("try...");
a = 3 / 0;
} catch (Exception e){
System.out.println("catch...");
} finally {
System.out.println("finally...");
a = 2;
}
return 100;
}
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try{ return; }catch(){} finally{} return
try中已经return，所以不再执行finally后面的return。
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| private static int returnInFinally_01(){
int a ;
try{
System.out.println("try...");
a = 3 / 1;
return a;
} catch (Exception e){
System.out.println("catch...");
} finally {
System.out.println("finally...");
a = 2;
}
return 100;
}
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try{ } catch(){return;} finally{} return
与上述情况类似
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| private static int returnInFinally_02(){
int a = 0;
try{
System.out.println("try...");
a = 3 / 0;
} catch (Exception e){
System.out.println("catch...");
return a;
} finally {
System.out.println("finally...");
a = 2;
}
return a;
}
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try{ return; }catch(){} finally{return;}
程序执行try块中return之前（包括return语句中的表达式运算）代码；再执行finally块，因为finally块中有return所以提前退出（这提前退出的意思是指：后面的代码都不会再执行了，所以就退出）。
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| private static int returnInFinally_03(){
int a ;
try{
System.out.println("try...");
a = 3 / 1;
return a;
} catch (Exception e){
System.out.println("catch...");
} finally {
System.out.println("finally...");
a = 2;
return a;
}
//return 100; 不可能执行此代码，编译器直接报错
}
// 2
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try{} catch(){return;}finally{return;}
与上述类似
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| private static int returnInFinally_04(){
int a = 0;
try{
System.out.println("try...");
a = 3 / 0;
} catch (Exception e){
System.out.println("catch...");
return a ++;
} finally {
System.out.println("finally...");
a ++;
return a;
}
}
// 2
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try{ return;}catch(){return;} finally{return;}
同上述类似
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| private static int returnInFinally_05(){
int a = 1;
try{
System.out.println("try...");
a = 3 / 0;
return a;
} catch (Exception e){
System.out.println("catch...");
return a ++;
} finally {
System.out.println("finally...");
a ++;
return a;
}
}
// 3
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return后在finally中修改值是否会影响结果？
问题回到传值还是传引用上啦，这里有疑问就再回去看看传值与传引用吧
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| // 一个普通测试类
private static class TestObject{
private int x;
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
// 覆盖toString
@Override
public String toString() {
return "x = " + x;
}
}
private static TestObject returnInFinally_06(){
TestObject to = new TestObject();
try{
System.out.println("try...");
to.setX(1);// 设为1
return to;
} catch (Exception e){
System.out.println("catch...");
to.setX(2);// 设为2
return to;
} finally {
System.out.println("finally...");
to.setX(3);// 最终设为3
}
}
// try...
// finally...
// x = 3
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