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x++ will increase a value sometimes. Please help me learn all of the times when it won't change x. This is my understanding so far: x=4; for { y=x++; } document.write(y) //returns 4 x=4; for { y=x++; y+=2; return y; } //returns 7 x++/2==? ++x/2=2.5
I was told X++ only increments if it is followed by code in a block. But what about in a math problem? or any other instance?
6 Réponses
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In second code block a value of y will be 6. And in third code block (if x = 4):
x++/2 // 2 is result
++x/2 // 2,5 is result
Because:
x++ will increase a value of x every time, but if you use it in expression it will return a value at first, and then increase a value.
There are a two types of increment: postfix (i++) and prefix (++i). Postfix return a value at first, and then increase a value. Prefix increase a value at first, and then return a value.
Here is an examples:
//#1
var x = 1;
var y = x++ + 3; // y=4, because postfix increment return a value in expression at first (x = 1). And then x will be increased (x = 2)
//#2
var x = 1;
var y = ++x + 3; // y=5, because prefix increment increase a value at first (x = 2), and then x returns this value in expression ( x = 2)
//#3
var x = 1;
var y = x++; // y = 1; x = 2;
y = ++x; // y = 3, x = 3
0
postfix x++ first use the value and then increase the value of x.
prefix ++x first increase the Value and then use value of x.
for example: x=0;
y=++x;
output: x=1,y=1
And if
x=0;
y=x++;
output: x=1,y=0
- 1
++name adds first then tag it to the place mentioned, but
name++ first tags it then adds it by one so the value is changed afterward...
- 2
Simply put
x++ will use the value of x, then increment x
++x will increment x, then use the new value of x
examples
x=0
y=x++
y now has value of 0
x now has value of 1
x=0
y=++x
y now has value of 1
x now has value of 1
- 2
how do I promote apps like in funadict com
- 2
when you use
b=1
a=b++ // a=1 and b=2
a=b // a=2 and b=2
a=++b // a=3 and b=3
c=5
d=c++ // d=5 c=6