diff --git "a/37 \346\217\255\351\230\263\344\270\275/20221201 java-if \350\257\255\345\217\245" "b/37 \346\217\255\351\230\263\344\270\275/20221201 java-if \350\257\255\345\217\245" deleted file mode 100644 index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..0000000000000000000000000000000000000000 diff --git "a/37 \346\217\255\351\230\263\344\270\275/20221204 for\345\276\252\347\216\257\350\257\255\345\217\245.txt" "b/37 \346\217\255\351\230\263\344\270\275/20221204 for\345\276\252\347\216\257\350\257\255\345\217\245.txt" new file mode 100644 index 0000000000000000000000000000000000000000..f9ac3f64e607be79538422aa99bc63512d32b201 --- /dev/null +++ "b/37 \346\217\255\351\230\263\344\270\275/20221204 for\345\276\252\347\216\257\350\257\255\345\217\245.txt" @@ -0,0 +1,119 @@ +### 笔记 + +#### if和Switch的区别 + +```java +Switch能做的if也能做,但if能做的Switch不一定能做 +if可以判断Switch的一个范围 +而Switch只能判断特定的一个值 +``` + +#### Switch + +```java +switch支持字符串,但不支持布尔值变量 +``` + +#### for循环 + +```java +for(初始化语句;条件语句;控制语句){ + 循环体;若干语句 +} +``` + +#### for循环乘法表 + +```java +package Work; + +public class D5 { + public static void main(String[] args) { + for (int i=1; i<=9;i++){ + for (int x=1; x<=i;x++){ + System.out.print(x+"*"+i+"="+(i*x)+" "); + } + System.out.println(""); + } + + } +} +``` + +#### for循环26字母,每两字母换行 + +```java +package Work; + +public class D4 { + public static void main(String[] args) { + char a=97; + int b=0; + for (a=97;a<=122;a++){ + if (b%2==0){ + System.out.println(); + } + System.out.print(a); + b++; + } + + + + } +} +``` + +#### for循环作业(1) + +##### 题目: + +让用户输入一个数字,根据这个数字,循环输出“我爱学习,我爱java”,比如,用户输入数字9就在控制台输出9行“我爱学习,我爱java” + +```java +package Work; + +import java.util.Scanner; + +public class D6 { + public static void main(String[] args) { + Scanner sc= new Scanner(System.in); + System.out.println("请输入数字"); + int a=sc.nextInt(); + for (int i=1;i<=a;i++){ + System.out.println( "我爱学习,我爱java"); + } + } +} +``` + +#### for循环作业(2) + +##### 题目: + +用户分别输入数a,数b,让程序实现从a开始循环到b,输出“有生之年,能看到中国队出线吗?” + +```java +package Work; + +import java.util.Scanner; + +public class D9 { + public static void main(String[] args) { + Scanner cs= new Scanner(System.in); + System.out.println("请输入a"); + int a= cs.nextInt(); + System.out.println("请输入b"); + int b=cs.nextInt(); + for (int i=a;inum){ + System.out.println("你猜的数字太大了!再猜"); + }else if (um1 && count<=6 && um==num){ + System.out.println("你很聪明"); + break; + }else { + System.out.println("猜对了!"); + System.out.println("你一共猜了"+count+"次"); + System.out.println("笨笨,你猜这么多次"); + break; + + } + } + } + } + +``` + +作业(2) + +```jav +package Work; + +public class A2 { + + public static void main(String[] args) { + int j=555555; + int i; + int k = 0; + for (i = 999; i >= 100; i--) { + k=j%i; + if(k==0){ + System.out.println(i); + break; + } + } + } + } +``` +