decrement

In Java, why can't I write i++++ or (i++)++?

由 。_饼干妹妹 提交于 2019-12-19 02:06:09
问题 When I try to write a postfix/prefix in/decrement, followed by a post/prefix in/decrement, I get the following error: Invalid argument to operation ++/-- . But, according to JLS: PostIncrementExpression: PostfixExpression ++ and PostfixExpression: Primary ExpressionName PostIncrementExpression PostDecrementExpression so writing: PostfixExpression ++ ++ should be possible... Any thoughts? 回答1: Note that the raw grammar lacks any semantics. It's just syntax, and not every syntactically valid

MySQL Auto Increment Columns on TRANSACTION, COMMIT, and ROLLBACK

由 狂风中的少年 提交于 2019-12-17 16:45:12
问题 When using MySQL START TRANSACTION and the decision is made by MySQL to roll back - In the case that a table had an AUTO_INCREMENT column - does the column get... decremented during the roll back? Or should it? I am having some issues where the transaction data is being properly rolled back - but it looks like the table was auto incremented and not decremented in the rollback. # BOTH TABLES START OUT EMPTY // TABLE1 ID is **auto_increment** START TRANSACTION; INSERT INTO `TABLE1` (`ID` ,`NAME

Behaviour of increment and decrement operators in Python

由 人盡茶涼 提交于 2019-12-16 19:52:49
问题 I notice that a pre-increment/decrement operator can be applied on a variable (like ++count ). It compiles, but it does not actually change the value of the variable! What is the behavior of the pre-increment/decrement operators (++/--) in Python? Why does Python deviate from the behavior of these operators seen in C/C++? 回答1: ++ is not an operator. It is two + operators. The + operator is the identity operator, which does nothing. (Clarification: the + and - unary operators only work on

Behaviour of increment and decrement operators in Python

由 人走茶凉 提交于 2019-12-16 19:52:03
问题 I notice that a pre-increment/decrement operator can be applied on a variable (like ++count ). It compiles, but it does not actually change the value of the variable! What is the behavior of the pre-increment/decrement operators (++/--) in Python? Why does Python deviate from the behavior of these operators seen in C/C++? 回答1: ++ is not an operator. It is two + operators. The + operator is the identity operator, which does nothing. (Clarification: the + and - unary operators only work on

Pre and Post Increment and Decrement in Java [duplicate]

由 点点圈 提交于 2019-12-13 10:15:11
问题 This question already has answers here : How do the post increment (i++) and pre increment (++i) operators work in Java? (14 answers) Closed 2 years ago . Day after tomorrow is my exam for Computers (JAVA) and I have a big problem in the above title. I understood what does post and pre increment and decrement means. But I can no understand what to do when the matter comes to a complex, long statement. One example for such question is below. class java_1 { public void main() { int x = 4; x +=

Swift countDown timer Logic

由 ≯℡__Kan透↙ 提交于 2019-12-13 01:44:05
问题 I'm creating a countdown timer by the day, hour and second. I'm currently storing them in a String array while also converting them into an Int ( using map() ) so that I can countdown/decrement when I make the values into a label. The current output when printing to the logs is: ["[68168]", "[68188]", "[68243]", "[68281]"] I'm having trouble forming the logic of a countDown function so that when seconds hits "0", 1 minute goes down, and after 59 minutes 1 hour is decremented, etc., until it

Why is `x— > 0` not undefined behaviour, while `x = x--` is?

由 坚强是说给别人听的谎言 提交于 2019-12-10 19:08:37
问题 As everyone knows, this loops through zero: while (x-- > 0) { /* also known as x --> 0 */ printf("x = %d\n", x); } But x = x-- yields undefined behaviour. Both examples need some 'return' value of x-- , which is not there I guess. How can it be that x-- > 0 is defined but x = x-- is not? 回答1: Because in x = x-- you're modifying the value of x twice without an intervening sequence point. So the order of operations is not defined. In x-- > 0 the value of x is modified once, and it is clearly

Accessing a variable of a thread from another thread in java

由 倾然丶 夕夏残阳落幕 提交于 2019-12-09 16:14:06
问题 I'm trying to access and modify a variable of a thread in another thread in java, and I really don't know how to do this. ex : Runnable r1 = new Runnable() { int value = 10; public void run() { // random stuff } } Runnable r2 = new Runnable() { public void run() { // of course the bellow line will not work r1.value--; // I want here to be able to decrement the variable "value" of r1 } } Thread t1 = new Thread(r1); Thread t2 = new Thread(r2); t1.start(); t2.start(); thank you if you have any

Decrement the Variable I'm Incrementing in for loop

由 為{幸葍}努か 提交于 2019-12-08 11:25:48
问题 kind of a newbie to Python and I've looked around a bit but haven't found a satisfying answer to my question. I'm doing some practice problems and I want to make a method that gets rid of duplicate values in a list. So far, this is my code: def noDouble(nums): for x in xrange(len(nums) - 2): if nums[x] == nums[x + 1]: nums.pop(x) x -= 1 return nums What I want to happen is that if there's a duplicate, pop off one of the duplicates and then move back again (so that if there are, say, 3

jQuery: Stop decrementing textbox value if value equals 0

由 旧巷老猫 提交于 2019-12-07 00:29:46
What I have: I have a readonly textbox and two links. The first link increments the value of the textbox by 1 whereas the second link decrements the value by 1. What I need: I need the textbox value to stop decrementing at zero (I don't want negative numbers). My code: jQuery: jQuery(".increment").on('click',function(){ jQuery(this).next(".amount input").val(parseInt(jQuery(this).next(".amount input").val())+1); }); jQuery(".decrement").on('click',function(){ jQuery(this).prev(".amount input").val(parseInt(jQuery(this).prev(".amount input").val())-1); }); Note: .next and .prev are used because
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