java字符串连接String、StringBuffer和StringBuilder_学习笔记

Java字符串连接再开发中随时用的，方法很多：

先看下下边的代码：

package com.meiyabaike.classx;

public class ClassxMathCalculate {
    public static void main(String[] args) {
        int i1 = 10;
        int i2 = 20;
        System.out.println("resultx1 :"+i1+i2);
        //Error: the operator - is undefined for the argument type(s) String, int
//        System.out.println("resultx2 :"+i1-i2);
        System.out.println("resultx3 :"+i1*i2);
        System.out.println("resultx4 :"+i1/i2);
        System.out.println("resultx5 :"+i1%i2);
    }
}
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