字符串示例
one thousand only
two hundred
twenty
seven
我如何改变一个大写字母的字符串的第一个字符,而不改变任何其他字母的情况?
更改之后应该是:
One thousand only
Two hundred
Twenty
Seven
注意:我不想使用apache.commons.lang.WordUtils来做这件事。
字符串示例
one thousand only
two hundred
twenty
seven
我如何改变一个大写字母的字符串的第一个字符,而不改变任何其他字母的情况?
更改之后应该是:
One thousand only
Two hundred
Twenty
Seven
注意:我不想使用apache.commons.lang.WordUtils来做这件事。
当前回答
在这里(希望这能让你明白):
/*************************************************************************
* Compilation: javac Capitalize.java
* Execution: java Capitalize < input.txt
*
* Read in a sequence of words from standard input and capitalize each
* one (make first letter uppercase; make rest lowercase).
*
* % java Capitalize
* now is the time for all good
* Now Is The Time For All Good
* to be or not to be that is the question
* To Be Or Not To Be That Is The Question
*
* Remark: replace sequence of whitespace with a single space.
*
*************************************************************************/
public class Capitalize {
public static String capitalize(String s) {
if (s.length() == 0) return s;
return s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
}
public static void main(String[] args) {
while (!StdIn.isEmpty()) {
String line = StdIn.readLine();
String[] words = line.split("\\s");
for (String s : words) {
StdOut.print(capitalize(s) + " ");
}
StdOut.println();
}
}
}
其他回答
在这里(希望这能让你明白):
/*************************************************************************
* Compilation: javac Capitalize.java
* Execution: java Capitalize < input.txt
*
* Read in a sequence of words from standard input and capitalize each
* one (make first letter uppercase; make rest lowercase).
*
* % java Capitalize
* now is the time for all good
* Now Is The Time For All Good
* to be or not to be that is the question
* To Be Or Not To Be That Is The Question
*
* Remark: replace sequence of whitespace with a single space.
*
*************************************************************************/
public class Capitalize {
public static String capitalize(String s) {
if (s.length() == 0) return s;
return s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
}
public static void main(String[] args) {
while (!StdIn.isEmpty()) {
String line = StdIn.readLine();
String[] words = line.split("\\s");
for (String s : words) {
StdOut.print(capitalize(s) + " ");
}
StdOut.println();
}
}
}
另外,Spring Framework中还有org.springframework.util.StringUtils:
StringUtils.capitalize(str);
如果你只想大写一个名为input的字符串的第一个字母,其余的保持不变:
String output = input.substring(0, 1).toUpperCase() + input.substring(1);
现在输出将有您想要的内容。在使用此方法之前,请检查您的输入至少是一个字符,否则将会出现异常。
最简单的方法是使用org.apache.commons.lang.StringUtils类
StringUtils.capitalize(Str);
我想在接受的答案上添加一个NULL检查和IndexOutOfBoundsException。
String output = input.substring(0, 1).toUpperCase() + input.substring(1);
Java代码:
class Main {
public static void main(String[] args) {
System.out.println("Capitalize first letter ");
System.out.println("Normal check #1 : ["+ captializeFirstLetter("one thousand only")+"]");
System.out.println("Normal check #2 : ["+ captializeFirstLetter("two hundred")+"]");
System.out.println("Normal check #3 : ["+ captializeFirstLetter("twenty")+"]");
System.out.println("Normal check #4 : ["+ captializeFirstLetter("seven")+"]");
System.out.println("Single letter check : ["+captializeFirstLetter("a")+"]");
System.out.println("IndexOutOfBound check : ["+ captializeFirstLetter("")+"]");
System.out.println("Null Check : ["+ captializeFirstLetter(null)+"]");
}
static String captializeFirstLetter(String input){
if(input!=null && input.length() >0){
input = input.substring(0, 1).toUpperCase() + input.substring(1);
}
return input;
}
}
输出:
Normal check #1 : [One thousand only]
Normal check #2 : [Two hundred]
Normal check #3 : [Twenty]
Normal check #4 : [Seven]
Single letter check : [A]
IndexOutOfBound check : []
Null Check : [null]