Why is the output C, and after the value in the if is assigned, the statement under if is not execut

public class test1{

public static void main(string args)

boolean b = true;

if(b=false) b=false is assigning a value to b, and this line ** is assigning a value first to make a judgment, at this time b is false, and it does not enter the branch.

a");else if(b)

b");else if(!b) //b = false !b is true, goes into the branch, and outputs c

c");else "d");

1. If (b=false) is equivalent to if((b=false)) is equivalent to if(true == (b=false)), because b has been assigned to false, so this condition is not valid, so it is judged down.

2. Because b is already false at this time, else if (b) is not valid, continue to judge.

3、else if (!b) holds, so output c.

If replaced with if (b==false), then:

1. Because b is true at this time, if (true==false) is not valid, continue to judge.

2. else if (b) is true, so output b.

Here the main distinction is that one equal sign is an assignment statement, and two equal signs are a statement to determine whether it is equal.

If you are afraid of a clerical error, you can write if (false == b) like this, at this time, if you accidentally miss an equal sign, then the grammatical error can be distinguished at a glance.

If and else will only execute one of them, not both.

How does this ** feel that there is a problem, what you meant was to say, if A is equal to C, output C, don't wait for output B?

The copy expression x=5 itself has a value, and this value is equal to the lvalue. In other words, the value of the formula x=5 is x, which means that it is 5. The answer value of the formula x=5 is 5 is not zero, which is true, and k=2 will be executed.

Generally speaking, the statement after if prohibits the use of single equals signs, that is, assignment numbers, in order to prevent errors.

If it is x=0, the value of this expression is 0, which is false, and the following statement will not be executed. It doesn't matter what software you compile with, it's dev or vs08.

The assignment statement is always true copy, so it should be executed.

Excellent programmers need to develop good habits, Du is best to judge that the statement is written as zhiif(5==x), even if the wrong dao input is missing a "=", that is, if(5=x), so that the compilation will report an error, if it is written as if(x==5), and the wrong input is if(x=5), the program will continue, and it will be difficult to check the error of the big program.

Personally, I feel that the "=" here is the assignment symbol, and the value after the equal sign is assigned to x, so that if must be true, and then because the condition of if is true, it is normal to output the value of k, personal opinion.

For the if statement, since bai

You know the inside du

The judgment statement is an expression, so when you want to assign a value to a variable in the statement, you should know the rules of assignment! Assignment is not the same as when it is equal! As you asked:

if(x=5) this is wrong, the compiler is not going to agree with such an expression, so it is considered false, do not execute k=2, the same as below!

The assignment operation returns an lvalue.

x=5 returns 5 true

x=0 returns 0 false

Either zero is true, eg.

if(a=5)

else d=3;

This statement has no syntax errors (there may be warnings) and is executable.

But this statement never gets a chance to execute the else part.

The result of the a=5 assignment expression is 5, when this expression appears in the position of the logical expression of the if statement, its calculation result is treated as a logical value, in the C language, the integer number is used to represent the logical quantity, and the non-zero represents "true", so this is a permanent true formula; The logical condition of this if is never false.

In other words, the logical condition expressed here is not "whether the content of a is equal to 5", but the data 5 is fed into variable a.

Not necessarily, depending on whether the value assigned to the variable is 0 or not

Try the following programs:

#include

void main()

The program outputs i=1, which means that the execution of the second if statement is executed.

It's to compile and see if there are any syntax errors!

If it is an assignment statement, the if statement is true.

If you have a value of 0, you can try it yourself.

No, only syntax compilation errors will occur, and if you can only use to determine whether it is equal or not.

Your current conditional statement is written as 2 statements:

Conditional statement a:if (xconditional statement b:if (x==y &&y==z) else executes conditional statement a, and the condition is satisfied Execute output statement 1;

Then execute the conditional statement b, the condition is not satisfied, and the output statement 3 is executed;

Let's change it to a statement with else if:

if (xelse if (x==y &&y==z) else ；

In this way, x

Don't hesitate yet, the answer is: d

Listen to me tell you about if(expressions, literals, constants, variables, etc.); As long as one of these final values is not 0, it means that the statement associated with if will not be executed, and it will be executed if it is not 0 anyway.

According to the above: the if statement in the question '''associates'' printf('***'）；Then the if() parentheses are obviously an assignment expression, which means that if will use the final value of x as the basis for whether the if-associated statement is executed.

It is clear that x=y+z; Final x = 0;

So the else statement part is executed

Expressing the abusive tenacity of high-end goods.

######；Because both y and z are 0; So the return value of the assignment statement is 0;

First of all, make sure that the number you entered can be correctly assigned to the variable x, according to the way you write it in scanf, it should be x520.

Because your judgment condition is and, you must have a number that satisfies 5,8,13 divisibility = 0 at the same time before it will be in the if statement.

Is there a number that is divisible by 5 8 13 at the same time ? Replace && with ||Look.

I don't have a problem.,It's best to use semicolons between assignment expressions.,Although I tried the answer, it didn't matter.,I don't know yours.,How did it start.,Just use you**.,I'm normal on this.。

It runs on my machine without any problems.