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TA貢獻(xiàn)1875條經(jīng)驗 獲得超3個贊
是的可以。下面是一個最終可以提高性能的實例:
條件編譯
public class ConditionalCompile { private final static boolean doSomething= false; if (doSomething) { // do first part. } if (doSomething) { // do second part. } if (doSomething) { // do third part. } if (doSomething) { // do finalization part. }}
public class ConditionalCompile { private final static boolean doSomething= false; if (false){ // do first part. } if (false){ // do second part. } if (false){ // do third part. } if (false){ // do finalization part. }}
public class ConditionalCompile { private final static boolean doSomething= false; public static void someMethodBetter( ) { // do first part. // do second part. // do third part. // do finalization part. }}
從而減少了任何過多的代碼,或任何不必要的有條件檢查。
public class Test { public static final void main(String[] args) { boolean x = false; if (x) { System.out.println("x"); } final boolean y = false; if (y) { System.out.println("y"); } if (false) { System.out.println("z"); } }}
javap -c Test.class
public class Test { public Test(); Code: 0: aload_0 1: invokespecial #8 // Method java/lang/Object."<init>":()V 4: return public static final void main(java.lang.String[]); Code: 0: iconst_0 1: istore_1 2: iload_1 3: ifeq 14 6: getstatic #16 // Field java/lang/System.out:Ljava/io/PrintStream; 9: ldc #22 // String x 11: invokevirtual #24 // Method java/io/PrintStream.println:(Ljava/lang/String;)V 14: iconst_0 15: istore_2 16: return}
x

TA貢獻(xiàn)1780條經(jīng)驗 獲得超1個贊
final
final
final
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