C、C++、 Javafor 和 while 循环的区别

for循环：

for 循环提供了一种编写循环结构的简洁方法。与 while 循环不同，for 语句在一行中使用初始化、条件和递增/递减，从而提供更短、更易于调试的循环结构。

句法：

for (initialization condition; testing condition; 
                              increment/decrement)
{
    statement(s)
}

流程图：

例子：

C

#include 
  
int main()
{
  
    int i = 0;
  
    for (i = 5; i < 10; i++) {
        printf("GFG\n");
    }
  
    return 0;
}

C++

#include 
using namespace std;
  
int main()
{
  
    int i = 0;
  
    for (i = 5; i < 10; i++) {
        cout << "GFG\n";
    }
  
    return 0;
}

Java

import java.io.*;
  
class GFG {
    public static void main(String[] args)
    {
  
        int i = 0;
  
        for (i = 5; i < 10; i++) {
            System.out.println("GfG");
        }
    }
}

输出：

GFG
GFG
GFG
GFG
GFG

while循环：

while 循环是一种控制流语句，它允许根据给定的布尔条件重复执行代码。 while 循环可以被认为是一个重复的 if 语句。
句法 ：

while (boolean condition)
{
   loop statements...
}

流程图：

例子：

C

#include 
  
int main()
{
  
    int i = 5;
  
    while (i < 10) {
        printf("GFG\n");
        i++;
    }
  
    return 0;
}

C++

#include 
using namespace std;
  
int main()
{
  
    int i = 5;
  
    while (i < 10) {
        i++;
        cout << "GFG\n";
    }
  
    return 0;
}

Java

import java.io.*;
  
class GFG {
    public static void main(String[] args)
    {
  
        int i = 5;
  
        while (i < 10) {
            i++;
            System.out.println("GfG");
        }
    }
}

输出：

GFG
GFG
GFG
GFG
GFG

这里有一些区别：

For loop	While loop
Initialization may be either in loop statement or outside the loop.	Initialization is always outside the loop.
Once the statement(s) is executed then after increment is done.	Increment can be done before or after the execution of the statement(s).
It is normally used when the number of iterations is known.	It is normally used when the number of iterations is unknown.
Condition is a relational expression.	Condition may be expression or non-zero value.
It is used when initialization and increment is simple.	It is used for complex initialization.
For is entry controlled loop.	While is also entry controlled loop.
for ( init ; condition ; iteration ) { statement(s); }	while ( condition ) { statement(s); }