Li Kou brush question diary /day4/6.26

Novice Village

Sunrise Sunset , There is always dawn

VScode function java project

Create a new window

CTRL+SHIFT+P, Enter... In the pop-up window create java, choice No build tools

Select a folder to store java Project code

Set project name

You can run java Code

while loop

do while loop

do{
 Code block 
}while( Boolean expression );

 do while Loop at least once , Because execute first do sentence , Then execute the judgment statement while, So execute the code block content at least once .

while loop

while( expression ){
 Code block ;
// Jump out of while Circular approach 
if(){
break
}
}

while(1)、while(2)、while(3) Both indicate that the condition is true , That is to say, not 0 The numbers of all mean true .

while If the expression of the loop is not satisfied , Do not execute once . 

Self incrementing sign i++ and ++i

i++ First operation , One more

++i Yes, add one first , Re operation

Java in i=i++ and i++

  In the above code , The last output i The value of is always 0,

because i First assign to i by 0, After one execution ,i The value of is 0, Proceed again i=i++, The assignment operation has been assigning i=0.

Modify the code

  The above code can realize i A change in the value of ,while Statement executed n Time ,i The value is n

Example

Their thinking ： First define the number of operations i, Create a while loop , Judge num Is it even , If yes num=num/2, No num=num-1.i++, Record the number of executions , Last return i

class Solution {
    public int numberOfSteps(int num) {
        int i=0;
        while(num != 0){
            if(num % 2 == 0){
                num=num/2;
            }
            else{
                num=num-1;
            }
            i++;
        }
        return i;
    }
}