Java String split()
java String split()方法根据给定的正则表达式拆分此字符串，并返回一个char数组。
内部实现
public String[] split(String regex, int limit) {
char ch = 0;
if (((regex.value.length == 1 &&
".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
(regex.length() == 2 &&
regex.charAt(0) == '\\' &&
(((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
((ch-'a')|('z'-ch)) < 0 &&
((ch-'A')|('Z-ch)) < 0)) &&
(ch < Character.MIN_HIGH_SURROGATE || ch > Character.MAX_LOW_SURROGATE)) {
int off = 0;
int next = 0;
boolean limited = limit >0;
ArrayList<String> list = new ArrayList<>();
while ((next = indexOf(ch, off)) != -1) {
if (!limited || list.size() < limit - 1) {
list.add(substring(off, next));
off = next + 1;
}
else {
// last one
//assert (list.size() == limit - 1);
list.add(substring(off, value.length));
off = value.length;
break;
}
}
return this if (off == 0) return new String[]{this};
if (!limited || list.size() < limit) list.add(substring(off, value.length));
int resultSize = list.size();
if (limit == 0) while (resultSize > 0 && list.get(resultSize - 1).length() == 0) resultSize--;
String[] result = new String[resultSize];
return list.subList(0, resultSize).toArray(result);
}
return Pattern.compile(regex).split(this, limit);
}
签名
java字符串中的split()方法有两个签名。
public String split(String regex)and,public String split(String regex, int limit)
参数
regex : 要应用于字符串的正则表达式。
限制: 限制数组中的字符串数。如果为零，将返回所有与正则表达式匹配的字符串。
返回
字符串数组
抛出
PatternSyntaxException 如果正则表达式的模式无效
自
1.4
Java字符串split()方法示例
给定的示例返回字符串中的单词总数，但不包括空格。它还包含特殊字符。
public class SplitExample{
public static void main(String args[]){
String s1="java string split method by lidihuo";
String[] words=s1.split("\\s");
//splits the string based on whitespace
for(String w:words){
System.out.println(w);
}
}
}
java
string
split
method
by
lidihuo
带有正则表达式和长度示例的Java String split()方法
public class SplitExample2{
public static void main(String args[]){
String s1="welcome to split world";
System.out.println("returning words:");
for(String w:s1.split("\\s",0)){
System.out.println(w);
}
System.out.println("returning words:");
for(String w:s1.split("\\s",1)){
System.out.println(w);
}
System.out.println("returning words:");
for(String w:s1.split("\\s",2)){
System.out.println(w);
}
}
}
returning words:
welcome
to
split
world
returning words:
welcome to split world
returning words:
welcome
to split world
带有正则表达式和长度示例2的Java String split()方法
在这里，我们将split limit作为第二个参数传递给此函数。这限制了分割字符串的数量。
public class SplitExample3 {
public static void main(String[] args) {
String str = "lidihuott";
System.out.println("Returning words:");
String[] arr = str.split("t", 0);
for (String w : arr) {
System.out.println(w);
}
System.out.println("Split array length: "+arr.length);
}
}
Returning words:
lidihuo
Split array length: 1
