blocks|key|769875|text|试一试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|769876|String+t2+=+String.valueOf(Float.valueOf(t1)+*+Float.valueOf(m1))|code-block|syntax|javascript|769877|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|$]]

try

<pre><code>String t2 = String.valueOf(Float.valueOf(t1) * Float.valueOf(m1))
</code></pre>

blocks|key|1911554|text|首先从String中获取值，然后用下面的方法将parsed+value相乘：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1911555|double+result+=+Double.parseDouble(t1+)+*+Double.parseDouble(m1);
String+t2+=+Double.toString(result+);+|code-block|syntax|javascript|1911556|在上看看|1911557|entityMap^0|3|6|N|C|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

First get the value from <code>String</code> and multiply the <code>parsed value</code> in following way:

<pre><code>double result = Double.parseDouble(t1 ) * Double.parseDouble(m1);
String t2 = Double.toString(result ); 
</code></pre>

Have a look on <a href="http://docs.oracle.com/javase/tutorial/java/data/converting.html" rel="nofollow">Conversion between Numbers and String</a>

blocks|key|767235|text|使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|767236|String+t2+=+String.valueOf(Integer.parseInt(t1)+*+Integer.parseInt(m1))+|code-block|syntax|javascript|767237|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|$]]

use

<pre><code>String t2 = String.valueOf(Integer.parseInt(t1) * Integer.parseInt(m1)) 
</code></pre>

blocks|key|4297763|text|*是未定义的，因为t1是字符串，并且字符串不能用于乘法。如果t1和m1是数字的字符串表示，则可以将它们转换为数字(选择整型、浮点型、双精度或应用程序中需要的任何值)，然后进行乘法。就像这样(变量名是非java风格的，以获得额外的可读性，无需大肆抨击)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4297764|++++String+t1++=+"1.5";
++++String+m1+=+"10";

++++float+t1_as_a_float+=+Float.parseFloat(t1);
++++float+m1_as_a_float+=+Float.parseFloat(m1);

++++float+t2_as_a_float+=+t1_as_a_float+*+m1_as_a_float;

++++String+t2+=+Float.toString(t2_as_a_float);|code-block|syntax|javascript|4297765|entityMap^0|0|1|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<code>*</code> is undefined because t1 is a String and Strings cant be used in multiplication. If t1 and m1 are stringrepresentations of numbers you can convert them to numbers (chose Integer, Float, Double or whatever is needed in your application) and then multiply. Like this (variable names are none-java-style for extra readability, no bashing about it):

<pre><code> String t1 = "1.5";
 String m1 = "10";

 float t1_as_a_float = Float.parseFloat(t1);
 float m1_as_a_float = Float.parseFloat(m1);

 float t2_as_a_float = t1_as_a_float * m1_as_a_float;

 String t2 = Float.toString(t2_as_a_float);
</code></pre>

blocks|key|4297782|text|Java不知道将两个任意字符串转换在一起是什么意思(即什么是“臭味”*“鲸鱼”？)。首先，您需要将字符串转换为数字，将这些数字相乘，然后将结果转换回字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4297783|try+{
++++double+t1_num+=+Double.valueOf(t1);
++++double+m1_num+=+Double.valueOf(m1);
++++double+t2_num+=+t1_num+*+m1_num;
++++String+t2+=+String.valueOf(t2_num);
}+catch+(NumberFormatException+e)+{
++++//+called+if+numbers+cannot+be+converted+to+Strings
}|code-block|syntax|javascript|4297784|当t1和m1包含非数字字符时，您需要使用try-catch块来处理这种情况，比如"Ryan1“或”15“。|4297785|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Java doesn't know what it means to convert two arbitrary Strings together (i.e. what's "smelly" * "whale"?). First you need to convert the Strings to numbers, multiply those numbers together, then convert the result back to a String.

<pre><code>try {
 double t1_num = Double.valueOf(t1);
 double m1_num = Double.valueOf(m1);
 double t2_num = t1_num * m1_num;
 String t2 = String.valueOf(t2_num);
} catch (NumberFormatException e) {
 // called if numbers cannot be converted to Strings
}
</code></pre>

You need the try-catch block to handle the cases when t1 and m1 contain non-digit characters, like "Ryan1" or "fifteen".

blocks|key|4297804|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4297805|+String+t1+=+"325486"；|blockquote|4297806|4297807|4297808|++++String+m1+=+"7868";

++++int+n1+=+Integer.parseInt(t1);

++++int+n2+=+Integer.parseInt(m1);

++++int+n3+=+n1+*+n2;

++++String+t2+=+String.format("%25d",+n3);|code-block|syntax|javascript|4297809|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|-4|4|5|6|M|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|N|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|O|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|P|7|@]|8|@]|9|$]]|$1|F|3|G|4|H|6|Q|7|@]|8|@]|9|$I|J]]|$1|K|3|-4|4|5|6|R|7|@]|8|@]|9|$]]]|L|$]]

<blockquote>
 String t1 = "325486";
</blockquote>

<pre><code> String m1 = "7868";

 int n1 = Integer.parseInt(t1);

 int n2 = Integer.parseInt(m1);

 int n3 = n1 * n2;

 String t2 = String.format("%d", n3);
</code></pre>

I want to multiply two String variables and want to store the answer in a new variable. How can I do this? 

I have already tried to do the simple:

<pre><code>String t2 = t1 * m1;
</code></pre>

The error was that <code>*</code> was undefined. So, I tried adding:

<pre><code>import java.math.'whatever';
</code></pre>

That didn't fix the error.

How do I multiply two String variables?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我想将两个字符串变量相乘，并将结果存储在一个新变量中。我该怎么做呢？我已经尝试做了简单的事情：String t2 = t1 * m1;错误是*未定义。因此，我尝试添加：import java.math.'whatever';这并没有修复错误。

问如何将两个字符串变量相乘？
EN

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问如何将两个字符串变量相乘？EN