统计字符串中英文字母、数字、空格、其他字符的个数?
public static void countNum(String str) {
int count1 = 0;
int count2 = 0;
int count3 = 0;
int count4 = 0;
int len = str.length();
for (int i = 0; i < len; i++) {
char c = str.charAt(i);
if(c>='a'&& c<='z'|| c>='A'&& c<='Z') {
count1++;
}else if(c>='0'&&c<='9') {
count2++;
}else if(c==' ') {
count3++;
}else {
count4++;
}
}
System.out.println("字符串长度"+len);
System.out.println("字母个数"+count1);
System.out.println("数字个数"+count2);
System.out.println("空格个数"+count3);
System.out.println("其他个数"+count4);
}
```