- 条件较少的情况下,编译器不会做任何优化(不优化比优化好),switch 底层汇编会出现 "cmp" 比较,效率和 if-else 相同。 - 条件较多的情况下,switch 会有算法寻址,效率比 if-else 高。 - 顺序完整的情况下,如果乱序, switch 底层优化没有任何影响。 - 顺序残缺的情况下,如果跨度不大, switch 底层优化会将...
public void ifTest(){ int num1; if(_NUM == 1){ num1 = 1; }else if(_NUM == 3){ num1 = 3; }else if(_NUM == 5){ num1 = 5; }else if(_NUM == 7){ num1 = 7; }else if(_NUM == 9){ num1 = 9; }else{ num1 = -1; } } } 1. 2. 3. 4. 5. 6. 7. 8...
从性能方面来看,"else if"通常比"switch()case"更快。因为"else if"的结构较为简单,只需要判断条件是否满足,而"switch()case"则需要判断多个条件是否满足。因此,当条件数量较少时,"else if"的性能通常优于"switch()case"。 但是,当条件数量较多时,"switch()case"的优势就显现出来了。因为"switch()case"是...
Switch与If--else的比较switch...case与if...else的根本区别在于:switch...case会生成一个跳转表来指示实际的case分支的地址,而这个跳转表的索引号与...值,知道找到符合条件的分支。如此看来,switch的效率确实比ifelse要高的多。 2.由上面的汇编代码可知道,switch...case占用较多的代码空间,因为它要生成跳表,...
A switch case statement is more readable compared to if-else statements. In the end, the choice is yours and I hope this blog helps lead you in the right path to making the most informed decision when to use an if-else statement verses a switch case!
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这样就会延伸出一个问题，就是入口处会有一大堆if判断。这样本身是没什么问题的，只是看起来比较别扭，...
MATLAB Basics: ‘Switch case’ vs. ‘If elseif’ Posted by Doug Hull, January 2, 2008 45 views (last 30 days) | 1 Likes | 28 comments This three minute video takes a look at the “Switch case” flow control statement and contrasts it with the more familiar “If elseif” flow...
This three minute video takes a look at the “Switch case” flow control statement and contrasts it with the more familiar “If elseif” flow control statement. Often times, people will use an “If elseif” statement where a “Switch case” statement is going to be cleaner and easier to...
switch case语句通常可以和 if else 语句互换 比如上面那个判断成绩等级的代码,也可以用 if else 语句来表示 例如: **case 10: case 9: printf("恭喜您!您的成绩为:优秀"); break;** 可以换成: **if (grade10 || grade9) { printf("恭喜您!您的成绩为:优秀"); }** 具体代码如下: #include <std...