The difference between adding first and then adding ++Difference analysis of a and a++

var a = 1
var b = 1
var c = 1
(a++)
(++b)
((c += 1))

var a = 1
var b = 1
var c = 1
(a++) // 1
(++b) // 2
((c += 1)) // 2

one、
++可以与输出语句写existone起，++写exist变量前and写exist变量后不是one个意思
++ i and i ++ 区别exist于运算顺序and结合方向。
existJavaScriptThere are two types of self-add operations，All operators are ++，The function is to add operators themselves 1。
in：
++ VAR It is called pre-self-added，The variables that follow perform self-add operations，Its operation is，Perform the self-add operation first，Quote againVARvalue。
VAR ++ It is called post-self addition，The variables preceding it perform self-add operations，Its operation is，Quote firstVARvalue，Then perform self-add operations。
如果自加语句独立成为one个单独的语句，Then the addition of the front and back is exactly the same。
for example单独的one行
a ++; and ++ a; 是one样的。
1
For example，Commonforcycle:
    for(i = 0; i < 100; i ++)
    for(i = 0; i < 100; ++i)
1
2
Used here ++ i and i ++ It's exactly the same，No difference。
two、
当运算变量本身value会exist自加语句中，Perform other operations at the same time，two者就有区别了。
for example
    var i = 0;
    while( i ++ < 10);
1
2
i会先and10Compare size，Then perform self-add。This wayi=10hour，退出cycle，再执行one次自加，After exitivalue为11。
If written
    while(++ i < 10);
1
Is it self-added first，Then with10Compare。这样existi=9hour，Add it first，geti=10,然后Compare就会退出cycle了。In this case，After exitivalue为10。
再举one个例子。
    var a, i = 10;
    a = i ++; //Here i must first assign value and then add it yourself.  After the statement is executed, a=10, i=11;1
2
If written：
    var a, i = 10;
    a = ++i; //herei要Add it first，再赋value。After the statement is executeda=11, i = 11;