我有一个这样的字符串：
mysz = "name=john age=13 year=2001";
我想删除字符串中的空格。我试过trim()，但这只会删除整个字符串前后的空格。我也尝试了replaceAll("\\W", "")，但随后= 也被删除了。
我怎样才能实现一个字符串：
mysz2 = "name=johnage=13year=2001"
【问题讨论】：
标签： java whitespace
您还可以查看下面的 Java 代码。以下代码不使用任何“内置”方法。
/**
* Remove all characters from an alphanumeric string.
*/
public class RemoveCharFromAlphanumerics {
public static void main(String[] args) {
String inp = "01239Debashish123Pattn456aik";
char[] out = inp.toCharArray();
int totint=0;
for (int i = 0; i < out.length; i++) {
System.out.println(out[i] + " : " + (int) out[i]);
if ((int) out[i] >= 65 && (int) out[i] <= 122) {
out[i] = ' ';
}
else {
totint+=1;
}
}
System.out.println(String.valueOf(out));
System.out.println(String.valueOf("Length: "+ out.length));
for (int c=0; c<out.length; c++){
System.out.println(out[c] + " : " + (int) out[c]);
if ( (int) out[c] == 32) {
System.out.println("Its Blank");
out[c] = '\'';
}
}
System.out.println(String.valueOf(out));
System.out.println("**********");
System.out.println("**********");
char[] whitespace = new char[totint];
int t=0;
for (int d=0; d< out.length; d++) {
int fst =32;
if ((int) out[d] >= 48 && (int) out[d] <=57 ) {
System.out.println(out[d]);
whitespace[t]= out[d];
t+=1;
}
}
System.out.println("**********");
System.out.println("**********");
System.out.println("The String is: " + String.valueOf(whitespace));
}
}
输入：
String inp = "01239Debashish123Pattn456aik";
输出：
The String is: 01239123456
【讨论】：
private String generateAttachName(String fileName, String searchOn, String char1) {
return fileName.replaceAll(searchOn, char1);
}
String fileName= generateAttachName("Hello My Mom","\\s","");
【讨论】：
提供了很多答案。我想给出一个比正则表达式更易读且更好的解决方案。
import java.io.IOException;
import org.apache.commons.lang.StringUtils;
public class RemoveAllWhitespaceTest {
public static void main(String[] args) throws IOException {
String str1 = "\n\tThis is my string \n \r\n !";
System.out.println("[" + str1 + "]");
System.out.println("Whitespace Removed:");
System.out.println("[" + StringUtils.deleteWhitespace(str1) + "]");
System.out.println();
}
}
【讨论】：
如果要删除字符串中的所有空格：
public String removeSpace(String str) {
String result = "";
for (int i = 0; i < str.length(); i++){
char c = str.charAt(i);
if(c!=' ') {
result += c;
}
}
return result;
}
【讨论】：
StringBuilder
我正在尝试一个聚合答案，我在其中测试删除字符串中所有空格的所有方法。 每种方法运行 100 万次，然后取平均值。注意：一些计算将用于汇总所有运行。
第二名
第三名
第四名
public class RemoveAllWhitespaces {
public static String Regex(String text){
return text.replaceAll("\\s+", "");
}
public static String ForLoop(String text) {
for (int i = text.length() - 1; i >= 0; i--) {
if(Character.isWhitespace(text.codePointAt(i))) {
text = text.substring(0, i) + text.substring(i + 1);
}
}
return text;
}
public static String StringBuilder(String text){
StringBuilder builder = new StringBuilder(text);
for (int i = text.length() - 1; i >= 0; i--) {
if(Character.isWhitespace(text.codePointAt(i))) {
builder.deleteCharAt(i);
}
}
return builder.toString();
}
}
import org.junit.jupiter.api.Test;
import java.util.function.Function;
import java.util.stream.IntStream;
import static org.junit.jupiter.api.Assertions.*;
public class RemoveAllWhitespacesTest {
private static final String longText = "123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222123 123 \t 1adc \n 222";
private static final String expected = "1231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc2221231231adc222";
private static final String shortText = "123 123 \t 1adc \n 222";
private static final String expectedShortText = "1231231adc222";
private static final int numberOfIterations = 1000000;
@Test
public void Regex_LongText(){
RunTest("Regex_LongText", text -> RemoveAllWhitespaces.Regex(text), longText, expected);
}
@Test
public void Regex_ShortText(){
RunTest("Regex_LongText", text -> RemoveAllWhitespaces.Regex(text), shortText, expectedShortText);
}
@Test
public void For_LongText(){
RunTest("For_LongText", text -> RemoveAllWhitespaces.ForLoop(text), longText, expected);
}
@Test
public void For_ShortText(){
RunTest("For_LongText", text -> RemoveAllWhitespaces.ForLoop(text), shortText, expectedShortText);
}
@Test
public void StringBuilder_LongText(){
RunTest("StringBuilder_LongText", text -> RemoveAllWhitespaces.StringBuilder(text), longText, expected);
}
@Test
public void StringBuilder_ShortText(){
RunTest("StringBuilder_ShortText", text -> RemoveAllWhitespaces.StringBuilder(text), shortText, expectedShortText);
}
private void RunTest(String testName, Function<String,String> func, String input, String expected){
long startTime = System.currentTimeMillis();
IntStream.range(0, numberOfIterations)
.forEach(x -> assertEquals(expected, func.apply(input)));
double totalMilliseconds = (double)System.currentTimeMillis() - (double)startTime;
System.out.println(
String.format(
"%s: %s ms (%s ms)",
testName,
totalMilliseconds / (double)numberOfIterations,
totalMilliseconds
)
);
}
}
【讨论】：
package com.sanjayacchana.challangingprograms;
public class RemoveAllWhiteSpacesInString {
public static void main(String[] args) {
String str = "name=john age=13 year=2001";
str = str.replaceAll("\\s", "");
System.out.println(str);
}
}
【讨论】：