class forDemo01 {publicstaticvoidmain(String[] args){for(int i =1; i <=10;i++){
System.out.println("你好,很高兴认识你!i="+i);}}}
class forDemo02 {publicstaticvoidmain(String[] args){int i2 =1;for(;;){
System.out.println("hhh ");//死循环哦~}}}
class forDemo03 {publicstaticvoidmain(String[] args){int count =3;for(int i =0,j=0; i < count; i++,j=j+2){
System.out.println("i="+i+"j="+j);//i=0j=0//i=1j=2//i=2j=4}}}
class forDemo04 {publicstaticvoidmain(String[] args){//循环条件时返回一个布尔值的表达式,表达式是能够比较复杂的//for循环//打印1~100,挑选出来9的倍数//整数的个数,变量记录int count//总和 int sumint sum=0;//初始化int count =0;//统计个数int starNum =1;int endNum =100;for(int i = starNum; i <= endNum; i++){if( i %9==0){
count++;
sum += i;
System.out.println("i="+i);}
System.out.println("从"+starNum +"到"+"endNum"+"的数字");
System.out.println("count="+count);
System.out.println("sum="+sum);}}}
class forDemo04 {publicstaticvoidmain(String[] args){//输出小写的a-z以及大写的Z—A【使用for循环】//第一种作法:char capitalLetters ='A';char LowercaseLetters ='a';for(int i =1; i <27; i++){//System.out.println("大写字母"+capitalLetters +"小写字母"+LowercaseLetters);
System.out.print(capitalLetters+"\t");
System.out.print(LowercaseLetters+"\t");
capitalLetters++;
LowercaseLetters++;}// 第二种作法:for(char a ='a'; a <'z'; a++){
System.out.print(a+"\t");}
System.out.println();for(char a ='A'; a >'Z'; a--){
System.out.print(a+"\t");}}}