习题6.2（求一个整数各位数之和） import; publicclasssumIf { publicstaticvoid main(String[] args) { // TODO Auto-generated method stub System.out.print("请输入一个整数："); longn = input.nextInt(); System.out.print("输入的整数i=" + n + "的各个数字的和是" + sumDigits(n)); publicstaticlongsumDigits(longk){ longsum = 0; while(k != 0) { sum += k % 10; k /= 10; } 习题6.4（反向显示一个整数） import; publicclass reverse { publicstaticvoid main(String[] args) { // TODO Auto-generated method stub System.out.print("请输入一个整数"); intnumber1 = input.nextInt(); reverse(number1); publicstaticintreverse(intnumber) { inti; } Scanner input = newScanner(System.in); } } returnsum; } Scanner input = newScanner(System.in); . while(number != 0){ System.out.print(number%10); number /= 10; } 习题6.6（显示图案，此方法只能在10以内对其） importjava.util.*; publicclass displayPattern1 { publicstaticvoid main(String[] args) { // TODO Auto-generated method stub System.out.print("请输入一个整数"); intn = input.nextInt(); displayPattern(n); } publicstaticvoiddisplayPattern(inti) { for(intj = 1; j <= i; j++) { for(intk = 0; k < i-j; k++) { System.out.print(" "); //if(j >= 10)(" "); } for(intk = j; k > 0; k--) { System.out.print(k + " "); } 程序清单6-1（调用max方法） publicclassTestMax { publicstaticvoid main(String[] args) { // TODO Auto-generated method stub } } } System.out.println(); Scanner input = newScanner(System.in); } } return 0; . inti = 5; intj = 2; intk = max(i, j); System.out.println("the maxinum of " + i + " and " + j + " is " + k); } publicstaticint max(intnum1, intnum2) { intresult; if (num1 > num2) result = num1; else result = num2; returnresult; } } 程序清单6-2（void方法示例，打印给定分数的等级） publicclassTestVoidMethod { publicstaticvoid main(String[] args) { // TODO Auto-generated method stub System.out.print("The grade is "); printGrade(78.5); System.out.print("The grade is "); printGrade(59.5); publicstaticvoidprintGrade(doublescore) { if(score >=90.0) { System.out.println('A'); } elseif(score >=80.0) { System.out.println('B'); } elseif(score >=70.0) { System.out.println('C'); } elseif(score >=60.0) { System.out.println('D'); } else { System.out.println('F'); } . 本文来源：https://www.wddqw.com/doc/9edc30f3f51fb7360b4c2e3f5727a5e9856a2770.html