groovy基本类型

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package primary

class TypeDemo {

    static void main(args) {

        int x = 5;

        long y = 100L;

        float a = 10.56f;

        double b = 10.5e40;

        BigInteger bi = 30g;

        BigDecimal bd = 3.5g;

        println(x);
        println(y);
        println(a);
        println(b);
        println(bi);
        println(bd);

        println("The value of x is " + x + "The value of y is " + y);
    }


}

groovy特殊运算符

1.范围运算符

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package primary

class OperatorDemo {

    static void main(String[] args) {
		
		//定义离散变量组，从0到10
        def range = 0..10 ;
		
        println(range);
        println(range.get(2));
    }
}

输出结果

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0..10
2

运算符优先级

++ ，-- ，+ ，- 预增/减（自增/减），一元加，一元减
*， /， ％ 乘法，除法，取模
+，- 加法，减法（二元）
==，！=， <=> 等于，不等于，比较运算符
＆ 二进制/位运算符与
^ 二进制/位异或
` `
！ 逻辑非
&& 逻辑与
`
=，+=，-=，*=，/=，%=，**= 各种赋值运算符

for-in语句

特殊循环，类似于java for 循环增强 

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package primary

class forDemo {

    static void main(String[] args) {

        def range = 0..10

        for (i in range) {
            println(i)
        }

        def users = ["z":21,"s":11]

        for(user in users){
            println(user.key+":"+user.value)
        }

    }
}

方法

函数列表默认值

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package primary;

class FunctionDemo {

    static void main(String[] args) {
        println (sum(1,1))
    }

    static int sum(int a, int b = 0) {
        a+b
    }
}

IO操作

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package io

class IOUtils {

    static void main(String[] args) {

        new File("E://data//test").eachLine {
            line -> println "line:$line"
        }

        //读取文件到字符串
        File file = new File("E://data//test")
        println file.text

        //写入文件
        new File("E://data//test").withWriter {
            writer -> writer.writeLine 'Hello World!'
        }

        println file.text

        //获取文件大小
        println "The file ${file.absolutePath} has ${file.length()} bytes"

        //判断文件是否是目录
        println "File? ${file.isFile()}"
        println "Directory? ${file.isDirectory()}"

        //创建文件目录
        def directory = new File('E:/groovy/Directory')
        directory.mkdirs()

        def newFile = new File(directory, "newFile")
        newFile.createNewFile()

        //复制文件
        def copyFile = new File(directory, "copyFile")
        copyFile << newFile

        println("copyFile is create:${copyFile.exists()}")

        copyFile.delete()
        println("copyFile is delete?${copyFile.exists()}")

        //显示根目录
        def rootFiles = new File("test").listRoots()
        rootFiles.each {println it.absolutePath}

        rootFiles.each {
            //遍历目录及子集
               it.eachFileRecurse(){recurse->
                    println(recurse.absolutePath)
               }

        }
    }
}