1 minute to understand the execution process and permanently master the for cycle (with for cycle cases)

:::info
according to Forgetting curve ： If there is no record and review ,6 Days later, I will forget 75% The content of
Reading notes are a tool to help you record and review , Don't stick to form , Its core is ： Record 、 Look over 、 reflection
:::

Conditions for using loops ：

An operation needs to be repeated several times

1 for loop

for Recycle format

for Circular use format ：
stay for In circulation , The initialization statement only executes 1 Time ;

for Circular case 1 Output three paragraphs in succession

//for Circular format ：

    for( Initialization statement ; Conditional statements ; Conditional control statements ){
    
       // Loop body statement ;
    }
//for Circular case ：
 public static void main(String[] args) {
    
        for(int i =0;i<3;i++){
    
            System.out.println(" Execution section "+i+" Secondary cycle ！");
        }
    }

for Circular execution flow （ A top priority ）

Perform process resolution , Statement module division , The illustration

 for( Initialization statement ; Conditional statements ; Conditional control statements ){
    
       // Loop body statement ;
    }

• for Circular case 2( The countdown to dry food )

//for Circular case 2( Dry meal countdown )
        for (int i=10;i>=0;i--){
    
            if (i !=0 ){
    
                System.out.println(" The countdown to dinner and "+i+" second ");
            }else {
    
                System.out.println(" It's time to start cooking ！");
            }
        }

• for Circular case 3(1-100 Even and )

//for Circular case 3（1-100 Between even numbers and ）
// Implementation scheme 1
        int sum =0;
        for (int i = 1;i<=100;i++){
    
            if (i%2==0){
    
                sum += i;
            }
        }
        System.out.println("1-100 The even number between and is ："+sum);
// Implementation scheme 2
        int sum =0;
        for (int i = 2;i<=100;i+=2){
    
                sum += i;
        }
        System.out.println("1-100 The even number between and is ："+sum);