我的程序中存在一个错误,它使我的循环只读取输入字符串的最后一部分。我希望程序计算字符串中每个字符的数量。我不希望答案告诉我如何更有效地存储这些值,而不是重复所有26次。请回答我在此处陈述的问题。对不起,如果这是重复的!我只是不知道要指定什么,因为没有明显的错误。
import java.util.Scanner;
public class stringprogram {
public static void stringinputmethod()
{
Scanner scan = new Scanner(System.in);
System.out.println("Enter a String");
String strs = scan.nextLine();
int numa = 0;
int numb = 0;
int numc = 0;
int numd = 0;
int nume = 0;
int numf = 0;
int numg = 0;
int numh = 0;
int numi = 0;
int numj = 0;
int numk = 0;
int numl = 0;
int numm = 0;
int numn = 0;
int numo = 0;
int nump = 0;
int numq = 0;
int numr = 0;
int nums = 0;
int numt = 0;
int numu = 0;
int numv = 0;
int numw = 0;
int numx = 0;
int numy = 0;
int numz = 0;
String randaf;
for(int i=0; i<=strs.length();i++)
{
randaf = strs.substring(i);
if(randaf.equals("a"))
{
numa = numa + 1;
}
else if(randaf.equals("b"))
{
numb = numb + 1;
}
else if(randaf.equals("c"))
{
numc = numc + 1;
}
else if(randaf.equals("d"))
{
numd = numd + 1;
}
else if(randaf.equals("e"))
{
nume = nume + 1;
}
else if(randaf.equals("f"))
{
numf = numf + 1;
}
else if(randaf.equals("g"))
{
numg = numg + 1;
}
else if(randaf.equals("h"))
{
numh = numh + 1;
}
else if(randaf.equals("i"))
{
numi = numi + 1;
}
else if(randaf.equals("j"))
{
numj = numj + 1;
}
else if(randaf.equals("k"))
{
numk = numk + 1;
}
else if(randaf.equals("l"))
{
numl = numl + 1;
}
else if(randaf.equals("m"))
{
numm = numm + 1;
}
else if(randaf.equals("n"))
{
numn = numn + 1;
}
else if(randaf.equals("o"))
{
numo = numo + 1;
}
else if(randaf.equals("p"))
{
nump = nump + 1;
}
else if(randaf.equals("q"))
{
numq = numq + 1;
}
else if(randaf.equals("r"))
{
numr = numr + 1;
}
else if(randaf.equals("s"))
{
nums = nums + 1;
}
else if(randaf.equals("t"))
{
numt = numt + 1;
}
else if(randaf.equals("u"))
{
numu = numu + 1;
}
else if(randaf.equals("v"))
{
numv = numv + 1;
}
else if(randaf.equals("w"))
{
numw = numw + 1;
}
else if(randaf.equals("x"))
{
numx = numx + 1;
}
else if(randaf.equals("y"))
{
numy = numy + 1;
}
else if(randaf.equals("z"))
{
numz = numz + 1;
}
}
System.out.println("a: "+numa +"\nb: "+ numb +"\nc: "+ numc +"\nd: "+ numd +"\ne: "+ nume +"\nf: "+ numf +"\ng: "+ numg +"\nh: "+ numh +"\ni: "+ numi +"\nj: "+ numj +"\nk: "+ numk +"\nl: "+ numl +"\nm: "+ numm +"\nn: "+ numn +"\no: "+ numo +"\np: "+ nump +"\nq: "+ numq +"\nr: "+ numr +"\ns: "+ nums +"\nt: "+ numt +"\nu: "+ numu +"\nv: "+ numv +"\nw: "+ numw +"\nx: "+ numx +"\ny: "+ numy +"\nz: "+ numz);
}
public static void main(String[] args)
{
stringinputmethod();
}
}
答案 0 :(得分:1)
substring方法将从指定的索引返回一个新字符串到字符串的结尾。你想要的是String.charAt(index),它将返回指定位置的char
答案 1 :(得分:1)
substring
将字符串中从给定索引返回到它的结尾。由于长于单个字符的字符串永远不能等于单个字符,因此满足任何条件的唯一位置是最后一个字符。您可以使用substring(i)
,或者更好,substring(i, i+1)
,而不是使用charAt(i)
- 只需注意它返回char
原语,而不是java.lang.String
对象。< / p>
话虽如此,整个构造有点麻烦。使用Map<Character,Integer>
:
// Initialization:
Map<Character,Integer> map = new HashMap<>();
for (char c = 'a'; c <= 'z'; ++c) {
map.put (c, 0);
}
// Going over the string:
for(char c : strs.toCharArray()) {
Integer i = map.get(c);
if (i != 0) {
map.put (c, i + 1);
}
}
或者更优化的表单可以使用一个数组,其中第一个元素表示'a'
的数量,第二个元素表示'b'
的数量等:
// Initialization:
int[] chars = new int[26];
for (i = 0; i < chars.length; ++i) {
chars[i] = 0;
}
// Going over the string:
for(char c : strs.toCharArray()) {
int i = c - 'a';
if (i >= 0 && i < chars.length) {
chars[i]++;
}
}
答案 2 :(得分:0)
randaf = strs.substring(i);
将此行更改为
randaf = strs.substring(i,i+1);
将for循环更改为i<strs.length()
并且不等于。
如果你想缩短程序,可以这样做。
int[] counts=new int[26];
for(int i=0;i<strs.length();i++)
counts[strs.charAt(i)-'a']++;
假设你只想数一个&#39;到&#39; z&#39;
答案 3 :(得分:-1)
好的,所以我在发布之后就把它弄好了。不过,谢谢你的帮助!我只是改变了substring
的范围来读取一个字符,而不是之后的所有字符。
我仍然没有解决我的长代码问题,但是嘿,它有效。
import java.util.Scanner;
public class stringprogram {
public static void stringinputmethod()
{
Scanner scan = new Scanner(System.in);
System.out.println("Enter a String");
String strs = scan.nextLine();
int numa = 0;
int numb = 0;
int numc = 0;
int numd = 0;
int nume = 0;
int numf = 0;
int numg = 0;
int numh = 0;
int numi = 0;
int numj = 0;
int numk = 0;
int numl = 0;
int numm = 0;
int numn = 0;
int numo = 0;
int nump = 0;
int numq = 0;
int numr = 0;
int nums = 0;
int numt = 0;
int numu = 0;
int numv = 0;
int numw = 0;
int numx = 0;
int numy = 0;
int numz = 0;
String randaf;
for(int i=0; i<=strs.length()-1;i++)
{
randaf = strs.substring(i, i+1);
if(randaf.equals("a"))
{
numa = numa + 1;
}
else if(randaf.equals("b"))
{
numb = numb + 1;
}
else if(randaf.equals("c"))
{
numc = numc + 1;
}
else if(randaf.equals("d"))
{
numd = numd + 1;
}
else if(randaf.equals("e"))
{
nume = nume + 1;
}
else if(randaf.equals("f"))
{
numf = numf + 1;
}
else if(randaf.equals("g"))
{
numg = numg + 1;
}
else if(randaf.equals("h"))
{
numh = numh + 1;
}
else if(randaf.equals("i"))
{
numi = numi + 1;
}
else if(randaf.equals("j"))
{
numj = numj + 1;
}
else if(randaf.equals("k"))
{
numk = numk + 1;
}
else if(randaf.equals("l"))
{
numl = numl + 1;
}
else if(randaf.equals("m"))
{
numm = numm + 1;
}
else if(randaf.equals("n"))
{
numn = numn + 1;
}
else if(randaf.equals("o"))
{
numo = numo + 1;
}
else if(randaf.equals("p"))
{
nump = nump + 1;
}
else if(randaf.equals("q"))
{
numq = numq + 1;
}
else if(randaf.equals("r"))
{
numr = numr + 1;
}
else if(randaf.equals("s"))
{
nums = nums + 1;
}
else if(randaf.equals("t"))
{
numt = numt + 1;
}
else if(randaf.equals("u"))
{
numu = numu + 1;
}
else if(randaf.equals("v"))
{
numv = numv + 1;
}
else if(randaf.equals("w"))
{
numw = numw + 1;
}
else if(randaf.equals("x"))
{
numx = numx + 1;
}
else if(randaf.equals("y"))
{
numy = numy + 1;
}
else if(randaf.equals("z"))
{
numz = numz + 1;
}
}
System.out.println("a: "+numa +"\nb: "+ numb +"\nc: "+ numc +"\nd: "+ numd +"\ne: "+ nume +"\nf: "+ numf +"\ng: "+ numg +"\nh: "+ numh +"\ni: "+ numi +"\nj: "+ numj +"\nk: "+ numk +"\nl: "+ numl +"\nm: "+ numm +"\nn: "+ numn +"\no: "+ numo +"\np: "+ nump +"\nq: "+ numq +"\nr: "+ numr +"\ns: "+ nums +"\nt: "+ numt +"\nu: "+ numu +"\nv: "+ numv +"\nw: "+ numw +"\nx: "+ numx +"\ny: "+ numy +"\nz: "+ numz);
}
public static void main(String[] args)
{
stringinputmethod();
}
}