for,while和do~while语句有何异同?

2025-03-28 19:28:01
推荐回答(5个)
回答1:

相同点:都是进行循环判断的
不同点:
do-while是先执行后判断,因此do-while至少要执行一次循环体。而while是先判断后执行,如果条件不满足,则一次循环体语句也不执行。
for(表达式1;表达式2;表达式3) 第一步,计算表达式1的值。第二步,计算表达式2的值。若值为真(非0)则执行循环体一次,否则跳出循环。第三步,计算表达式3的值,转回第二步重复执行

回答2:

我水平比较低,感觉其实都差不多,有点小差别。
for先判断条件成立不成立,然后再决定执行不执行。
while同for,不过while的判断面比for广一些。
for大多数用来控制循环次数,
典型的有:
for(i=1;i<3;i++)
while的判断范围比for广,比如:
i=1;
while(i<3){
...
...
i++;
}
while(a=b){
.....
}
do~while与while的区别在于,while是“先判断条件是否成立,再决定是否执行循环”do~while是“不管判断条件是否成立,先执行一次再说,执行一次以后再通过判断,看看是否再次执行”

回答3:

都是循环语句,用法不同。
for(;;)根据初始条件,循环限制条件来控制循环

while(){}先判断条件再循环执行

do{}while()至少执行一次,再判断while条件

回答4:

基本可以通用,但for一般用于循环次数确定的场合,while和do while用于循环次数不确定的场合,do while适合用于写了循环体后才好写表达式的场合,例如:辗转相除法求两数的最大公约数

回答5:

while 循环:是先要进行判断,如果条件不满足,继续循环,满足则跳出循环。
do..while循环:是先进行循环,然后判断条件是否满足,如果条件不满足,继续循环,满足则跳出循环(至少执行1次循环).

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