blocks|key|835805|text|这是因为j%2B3不会改变j的值。您需要将其替换为j+=+j+%2B+3或j+%2B=+3，以便j的值增加3：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|835806|for+(j+=+0;+j+<=+90;+j+%2B=+3)+{+}|code-block|syntax|javascript|835807|entityMap^0|4|3|B|1|N|9|X|6|16|1|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|L|$]]

That’s because <code>j+3</code> doesn’t change the value of <code>j</code>. You need to replace that with <code>j = j + 3</code> or <code>j += 3</code> so that the value of <code>j</code> is increased by 3:

<pre><code>for (j = 0; j &lt;= 90; j += 3) { }
</code></pre>

blocks|key|1050367|text|在您的示例中，j%2B=3递增3。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1050368|(这里没有太多要说的，如果与语法相关，我建议先搜索Googling，但我是新来的，所以我可能会错。)|1050369|entityMap^0|7|4|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|N|8|@]|D|@]|E|$]]]|I|$]]

In your example, <code>j+=3</code> increments by 3.

(Not much else to say here, if it's syntax related I'd suggest Googling first, but I'm new here so I could be wrong.)

blocks|key|1050445|text|for(j+=+0;+j<=90;+j+=+j%2B3)
{

}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1050446|j%2B3不会将新值赋给j，add+j=j%2B3会将新值赋给j，循环将上移3。|unstyled|offset|length|style|CODE|1050447|j%2B%2B类似于说j+=+j%2B1，所以在这种情况下，您可以将新值赋给j，就像上面一样。|1050448|entityMap^0|0|0|3|G|5|0|0|3|7|7|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|P|8|@$G|Q|H|R|I|J]|$G|S|H|T|I|J]]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@$G|V|H|W|I|J]|$G|X|H|Y|I|J]]|9|@]|A|$]]|$1|M|3|-4|5|F|7|Z|8|@]|9|@]|A|$]]]|N|$]]

<pre><code>for(j = 0; j&lt;=90; j = j+3)
{

}
</code></pre>

<code>j+3</code> will not assign the new value to j, add <code>j=j+3</code> will assign the new value to j and the loop will move up by 3. 

<code>j++</code> is like saying <code>j = j+1</code>, so in that case your assigning the new value to j just like the one above.

blocks|key|1050580|text|变化|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1050581|for(j+=+0;+j<=90;+j%2B3)|code-block|syntax|javascript|1050582|至|1050583|for(j+=+0;+j<=90;+j=j%2B3)|1050584|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Change 

<pre><code>for(j = 0; j&lt;=90; j+3)
</code></pre>

to 

<pre><code>for(j = 0; j&lt;=90; j=j+3)
</code></pre>

blocks|key|1050677|text|应该是这样的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1050678|for(int+j+=+0;+j<=90;+j+%2B=+3)+|code-block|syntax|javascript|1050679|但要当心|1050680|for(int+j+=+0;+j<=90;+j+=%2B+3)+|1050681|或|1050682|for(int+j+=+0;+j<=90;+j+=+j+%2B+3)|1050683|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

It should be like this

<pre><code>for(int j = 0; j&lt;=90; j += 3) 
</code></pre>

but watch out for 

<pre><code>for(int j = 0; j&lt;=90; j =+ 3) 
</code></pre>

or 

<pre><code>for(int j = 0; j&lt;=90; j = j + 3)
</code></pre>

blocks|key|1050873|text|简单地试一下这个|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1050874|for(int+i=0;+i<5;+i=i%2B2){//value+increased+by+2
//body
}|code-block|syntax|javascript|1050875|或|1050876|for(int+i=0;+i<5;+i%2B=2){//value+increased+by+2
//body
}|1050877|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Simply try this

<pre><code>for(int i=0; i&lt;5; i=i+2){//value increased by 2
//body
}
</code></pre>

OR

<pre><code>for(int i=0; i&lt;5; i+=2){//value increased by 2
//body
}
</code></pre>

blocks|key|836113|text|for(j+=+0;+j<=90;+j%2B%2B){}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|836114|j%2B%2B的意思是j=j%2B1，j值已经是0了，现在我们加1，所以现在j%2B1的和值变成了1，最后我们用和值(1)覆盖了j值(0)，所以这里我们用j%2B1覆盖了j值，所以每次迭代j值都会递增1。|unstyled|836115|for(j+=+0;+j<=90;+j%2B3){}|836116|这里j%2B3表示j的值已经是0了，现在我们加上3，所以现在j%2B3的总和变成了3，但是我们没有覆盖现有的j值。因此，JVM询问程序员，您正在计算新值，但是您将该值赋给一个变量(即j)。这就是为什么我们会收到编译时错误“invalid+AssignmentOperator”的原因。|836117|如果我们想要将j值增加3，那么我们可以使用下面的任何一种方法。|836118|+for+(int+j=0;+j<=90;+j%2B=3)++-->+here+each+iteration+j+value+will+be+incremented+by+3.
+for+(int+j=0;+j<=90;+j=j%2B3)+-->+here+each+iteration+j+value+will+be+incremented+by+3.++|836119|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$B|C]]|$1|O|3|-4|5|F|7|W|8|@]|9|@]|A|$]]]|P|$]]

<pre><code>for(j = 0; j&lt;=90; j++){}
</code></pre>

j++ means j=j+1, j value already 0 now we are adding 1 so now the sum value of j+1 became 1, finally we are overriding the j value(0) with the sum value(1)
 so here we are overriding the j value by j+1. So each iteration j value will be incremented by 1.

<pre><code>for(j = 0; j&lt;=90; j+3){}
</code></pre>

Here j+3 means j value already 0 now we are adding 3 so now the sum value of j+3 became 3 but we are not overriding the existing j value. So that JVM asking the programmer, you are calculating the new value but where you are assigning that value to a variable(i.e j). That's why we are getting the compile-time error " invalid AssignmentOperator ".

If we want to increment j value by 3 then we can use any one of the following way.

<pre><code> for (int j=0; j&lt;=90; j+=3) --&gt; here each iteration j value will be incremented by 3.
 for (int j=0; j&lt;=90; j=j+3) --&gt; here each iteration j value will be incremented by 3. 
</code></pre>

blocks|key|836201|text|您还可以将代码编写为|type|unstyled|depth|inlineStyleRanges|entityRanges|data|836202|for(int+i=0;i<n;i%2B%2B)
{
++++++//statements;
++++++i=i%2B2;//cause+you+want+to+increment+i+by+3+
}|code-block|syntax|javascript|836203|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can also write code as 

<pre><code>for(int i=0;i&lt;n;i++)
{
 //statements;
 i=i+2;//cause you want to increment i by 3 
}
</code></pre>

blocks|key|1050992|text|这只是一个语法错误。您只需用j=j%2B3或j%2B=3替换j%2B3即可。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1050993|entityMap^0|E|5|K|4|Q|3|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

It's just a syntax error. You just have to replace <code>j+3</code> by <code>j=j+3</code> or <code>j+=3</code>.

blocks|key|1050633|text|循环语句的“增量”部分必须更改index变量的值才能生效。"%2B%2Bj“的手写形式是"j+=j%2B+1”。所以，正如其他答案所说，增量的正确形式是"j+=j%2B+3"，这不是一个简单的递增1的缩写。"j+%2B+3"，正如你现在所知道的，实际上不会改变j；它是一个表达式，它的求值没有任何影响。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1050634|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The "increment" portion of a loop statement has to change the value of the index variable to have any effect. The longhand form of "++j" is "j = j + 1". So, as other answers have said, the correct form of your increment is "j = j + 3", which doesn't have as terse a shorthand as incrementing by one. "j + 3", as you know by now, doesn't actually change j; it's an expression whose evaluation has no effect.

blocks|key|836021|text|如果你有一个这样的for循环：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|836022|for(j+=+0;+j<=90;+j%2B%2B){}|code-block|syntax|javascript|836023|在此循环中，您将使用Java语言提供的速记，这意味着后缀操作符(使用-然后-更改)等同于j=j%2B1，因此更改后的值将被初始化并用于下一次操作。|836024|for(j+=+0;+j<=90;+j%2B3){}|836025|在这个循环中，您只是将值递增3，而不是将其初始化为j变量，因此j的值保持不变。|836026|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

If you have a for loop like this:

<pre><code>for(j = 0; j&lt;=90; j++){}
</code></pre>

In this loop you are using shorthand provided by java language which means a postfix operator(use-then-change) which is equivalent to j=j+1 , so the changed value is initialized and used for next operation.

<pre><code>for(j = 0; j&lt;=90; j+3){}
</code></pre>

In this loop you are just increment your value by 3 but not initializing it back to j variable, so the value of j remains changed.

blocks|key|836299|text|for+(let+i+=+0;+i+<=+value;+i%2B=n)+{+//+increments+by+n
/*code+statement*/
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|836300|此格式适用于我，将索引递增n|unstyled|836301|for+(let+i+=+0;+i+<=+value;+i%2B=4)+{+//+increments+by+4
/*code+statement*/
}|836302|如果n=4，它将递增4|836303|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>for (let i = 0; i &lt;= value; i+=n) { // increments by n
/*code statement*/
}
</code></pre>

this format works for me incrementing index by n

<pre><code>for (let i = 0; i &lt;= value; i+=4) { // increments by 4
/*code statement*/
}
</code></pre>

if n = 4 this it will increment by 4

If you have a for loop like this:

<pre><code>for(j = 0; j&lt;=90; j++){}
</code></pre>

It works fine. But when you have a for loop like this:

<pre><code>for(j = 0; j&lt;=90; j+3){}
</code></pre>

it doesn't work. Could someone please explain this to me?

How to make for loops in Java increase by increments other than 1

如果你有一个这样的for循环：for(j = 0; j<=90; j++){}它工作得很好。但是当你有一个这样的for循环时：for(j = 0; j<=90; j+3){}它不起作用。有人能给我解释一下吗？

问如何使Java中的循环按1以外的增量递增
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问如何使Java中的循环按1以外的增量递增
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