\u4e3a\u4e86\u63d0\u9ad8\u7a0b\u5e8f\u6267\u884c\u7684\u6027\u80fd\uff0c\u7f16\u8bd1\u5668\u548c\u5904\u7406\u5668\u4f1a\u5bf9\u6307\u4ee4\u8fdb\u884c\u91cd\u65b0\u6392\u5e8f\uff0c\u4f46\u91cd\u65b0\u6392\u5e8f\u7684\u4e00\u4e2a\u524d\u63d0\u6761\u4ef6\u662f\u300e\u4e0d\u80fd\u6539\u53d8\u7a0b\u5e8f\u5728\u5355\u7ebf\u7a0b\u72b6\u6001\u4e0b\u6267\u884c\u7684\u7ed3\u679c\u300f\u3002<\/p>\n\n\n\n
\u4e3e\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
int a = 10;\nboolean flag = true; \nif (flag) {\n int result = a * a;\n} else {\n int result = a + a;\n}<\/code><\/pre>\n\n\n\n\u7b2c\u4e00\u884c\u4ee3\u7801 int a = 10; \u548c\u7b2c\u4e8c\u884c\u4ee3\u7801 boolean flag = true; \u7684\u6267\u884c\u987a\u5e8f\uff0c\u5c31\u53ef\u4ee5\u88ab\u300e\u91cd\u6392\u5e8f\u300f\uff08\u8fd9\u91cc\u53ea\u662f\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u4e0d\u662f\u8bf4\u7f16\u8bd1\u5668\u5c31\u4e00\u5b9a\u4f1a\u5bf9\u8fd9\u4e24\u884c\u4ee3\u7801\u8fdb\u884c\u91cd\u6392\u5e8f\uff09\uff0c\u56e0\u4e3a\u8fd9\u4e24\u884c\u4ee3\u7801\u7684\u6267\u884c\u987a\u5e8f\u4e0d\u4f1a\u5f71\u54cd\u6700\u7ec8\u7684\u53d8\u91cf result \u7684\u7ed3\u679c\u662f 100\uff0c\u5728\u5355\u7ebf\u7a0b\u7684\u60c5\u51b5\u4e0b\uff0c\u8fd9\u6837\u7684\u91cd\u6392\u5e8f\u662f\u6ca1\u95ee\u9898\u7684\uff0c\u56e0\u4e3a\u6700\u7ec8\u7684\u8ba1\u7b97\u7ed3\u679c\u662f\u6b63\u786e\u7684\u3002<\/p>\n\n\n\n
\u4f46\u662f\u5728\u591a\u7ebf\u7a0b\u7684\u60c5\u51b5\u4e0b\uff0c\u4e0a\u8ff0\u6307\u4ee4\u91cd\u6392\u5e8f\u5c31\u53ef\u80fd\u4f1a\u4ea7\u751f\u95ee\u9898\u3002<\/p>\n\n\n\n
public class TestObj {\n int a = 1;\n boolean flag = false;\n public void init() {\n a = 100;\n flag = true;\n }\n public void run() {\n if (flag) {\n int result = a * a;\n System.out.println(\"result\u7684\u503c\u662f:\" + result);\n } else {\n int result = a + a;\n System.out.println(\"result\u7684\u503c\u662f:\" + result);\n }\n }\n }<\/code><\/pre>\n\n\n\n\u770b\u4e0a\u9762\u4ee3\u7801\uff0c\u5355\u7ebf\u7a0b\u60c5\u51b5\u4e0b\uff0c\u5148\u8c03\u7528 init() \u65b9\u6cd5\u8bbe\u7f6e a = 100; \u548c flag = true; \uff0c\u518d\u8c03\u7528 run() \u65b9\u6cd5\uff0cinit() \u65b9\u6cd5\u8bbe\u7f6e a = 100; \u548c flag = true; \u8fd9\u4e24\u884c\u4ee3\u7801\u7684\u987a\u5e8f\u5982\u679c\u53d1\u751f\u4e86\u91cd\u6392\u5e8f\uff08\u5373\u5148\u6267\u884c flag = true; \u518d\u6267\u884c a = 100\uff09\u4e5f\u4e0d\u4f1a\u5f71\u54cd run() \u65b9\u6cd5\u6267\u884c\u7684\u7ed3\u679c\uff08\u5373 result \u6700\u7ec8\u7b49\u4e8e 10000\uff09\uff0c\u6240\u4ee5\u7f16\u8bd1\u5668\u6216\u5904\u7406\u5668\u6709\u53ef\u80fd\u5bf9\u8fd9\u4e24\u884c\u4ee3\u7801\u505a\u91cd\u6392\u5e8f\u3002<\/p>\n\n\n\n
\u4f46\u662f\u5728\u591a\u7ebf\u7a0b\u60c5\u51b5\u4e0b\uff0c\u4e0a\u9762\u7684\u91cd\u6392\u5e8f\u5c31\u53ef\u80fd\u4ea7\u751f\u95ee\u9898\uff0c\u6bd4\u5982\u7f16\u8bd1\u5668\u6216\u5904\u7406\u5668\u5bf9 a = 100; \u548c flag = true; \u8fdb\u884c\u91cd\u6392\u5e8f\u540e\u53d8\u6210\u4e86\u5148 flag = true; \u7136\u540e a = 100; \uff0c\u90a3\u4e48\u5f53\u7ebf\u7a0b1 \u6267\u884c\u4e86 flag = true; \u540e\u5931\u53bb\u4e86 CPU \u4f7f\u7528\u6743\uff0c\u7ebf\u7a0b2 \u5f00\u59cb\u6267\u884c run() \u65b9\u6cd5\u5224\u65ad flag \u7684\u503c\u662f true \u5c31\u6267\u884c\u4e86 int result = a * a; \uff0c\u800c\u6b64\u65f6 a = 1\uff0c\u6240\u4ee5\u6700\u7ec8 result \u7684\u7ed3\u679c\u5c31\u662f 1 \u4e86\u3002<\/p>\n\n\n\n
\u600e\u4e48\u7981\u6b62\u8fd9\u79cd\u91cd\u6392\u5e8f\u5462\uff1f\u6211\u4eec\u53ea\u7528\u7528 volatile \u5bf9 flag \u53d8\u91cf\u8fdb\u884c\u4fee\u9970\u5373\u53ef\uff0c\u7136\u540e\u9488\u5bf9 flag \u53d8\u91cf\u7684\u64cd\u4f5c\u5c31\u4f1a\u6309\u7167\u4f60\u6e90\u7801\u4e2d\u7684\u987a\u5e8f\u6267\u884c\uff0c\u4e0d\u4f1a\u518d\u5bf9\u5176\u8fdb\u884c\u91cd\u6392\u5e8f\u3002<\/p>\n\n\n\n