JAVA - String 中删除指定字符(11种方法)






作者:CoderPLDQ



https://blog.csdn.net/li767517488/article/details/64919194






这边给大家介绍一下,String中是如何删除指定字符,博主粗略总结了11种方法,如果有不足或者遗漏希望读者能够不吝赐教。

第一种方法

通过循环从前往后遍历,如果不是要删除的字符则加到处理后的字符串中,代码如下:

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public String deleteCharString0(String sourceString, char chElemData) {
String deleteString = "";
for (int i = 0; i < sourceString.length(); i++) {
if (sourceString.charAt(i) != chElemData) {
deleteString += sourceString.charAt(i);
}
}
return deleteString;
}

第二种方法

通过循环确定要删除字符的位置索引,然后通过分割字符串的形式,将子字符串拼接,注意最后一段子字符串和源字符串中没有要删除字符的情况,代码如下:

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public String deleteCharString1(String sourceString, char chElemData) {
String deleteString = "";
int iIndex = 0;
for (int i = 0; i < sourceString.length(); i++) {
if (sourceString.charAt(i) == chElemData) {
if (i > 0) {
deleteString += sourceString.substring(iIndex, i);
}
iIndex = i + 1;
}
}
if (iIndex <= sourceString.length()) {
deleteString += sourceString.substring(iIndex, sourceString.length());
}
return deleteString;
}

第三种方法

原理同上,只不过查找要删除字符位置采用String类中的函数执行,效率不如上面的高,代码如下:

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public String deleteCharString2(String sourceString, char chElemData) {
String deleteString = "";
int iIndex = 0;
int tmpCount = 0;
do {
tmpCount = sourceString.indexOf(chElemData, iIndex);
if (tmpCount > 0) {
deleteString += sourceString.substring(iIndex, tmpCount);
}
if (tmpCount != -1) {
iIndex = tmpCount + 1;
}
} while (tmpCount != -1);
if (iIndex <= sourceString.length()) {
deleteString += sourceString.substring(iIndex, sourceString.length());
}
return deleteString;
}

第四种方法

原理与上方基本一致,只不过这次采用倒序方式,这里的坑就更多了,一定要注意索引的取值范围和是否合法,代码如下:

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public String deleteCharString3(String sourceString, char chElemData) {
String deleteString = "";
int iIndex = sourceString.length();
int tmpCount = 0;
do {
tmpCount = sourceString.lastIndexOf(chElemData, iIndex - 1);
if (tmpCount < sourceString.length() && tmpCount >= 0) {
deleteString = sourceString.substring(tmpCount + 1, iIndex) + deleteString;
}
if (tmpCount != -1) {
iIndex = tmpCount;
}
} while (tmpCount != -1);
if (iIndex >= 0) {
deleteString = sourceString.substring(0, iIndex) + deleteString;
}

return deleteString;
}

第五种方法

通过采用正则的方式和replaceAll函数,本种方法要注意特殊字符,例如正则中的 “.”字符,需要对特殊字符进行转义,代码如下:

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public String deleteCharString4(String sourceString, char chElemData) {
String deleteString = "";
final String strTable = "|^$*+?.(){}\\";
String tmpRegex = "[";
for (int i = 0; i < strTable.length(); i++) {
if (strTable.charAt(i) == chElemData) {
tmpRegex += "\\";
break;
}
}
tmpRegex += chElemData + "]";
deleteString = sourceString.replaceAll(tmpRegex, "");
return deleteString;
}

第六种方法

采用正则的方式将字符串分割成几个子字符串,再将子字符串进行拼接,代码如下:

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public String deleteCharString5(String sourceString, char chElemData) {
String deleteString = "";
final String strTable = "|^$*+?.(){}\\";
String tmpRegex = "[";
for (int i = 0; i < strTable.length(); i++) {
if (strTable.charAt(i) == chElemData) {
tmpRegex += "\\";
break;
}
}
tmpRegex += chElemData + "]";
String[] tmpStringArray = sourceString.split(tmpRegex);
for (int i = 0; i < tmpStringArray.length; i++) {
deleteString += tmpStringArray[i];
}
return deleteString;
}

第七种方法

将字符编程可读序列,在通过 String 类中的方法替换,代码如下:

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public String deleteCharString6(String sourceString, char chElemData) {
String tmpString = "";
tmpString += chElemData;
tmpString.subSequence(0, 0);
String deleteString = "";
deleteString = sourceString.replace(tmpString, deleteString.subSequence(0, 0));
return deleteString;
}

第八种方法

把原字符串转化为字符数组,然后原理与直接插入排序原理类似,代码如下:

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public String deleteCharString7(String sourceString, char chElemData) {
String deleteString = "";
char[] Bytes = sourceString.toCharArray();
int iSize = Bytes.length;
for (int i = Bytes.length - 1; i >= 0; i--) {
if (Bytes[i] == chElemData) {
for (int j = i; j < iSize - 1; j++) {
Bytes[j] = Bytes[j + 1];
}
iSize--;
}
}
for (int i = 0; i < iSize; i++) {
deleteString += Bytes[i];
}
return deleteString;
}

第九种方法

原理与 第一种方法 类似,本次采用 stringBuffer 类中的 append 方法进行操作,我认为效率应该高于第一种。

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public String deleteCharString8(String sourceString, char chElemData) {
StringBuffer stringBuffer = new StringBuffer("");
for (int i = 0; i < sourceString.length(); i++) {
if (sourceString.charAt(i) != chElemData) {
stringBuffer.append(sourceString.charAt(i));
}
}
return stringBuffer.toString();
}

第十种方法

采用 stringBuffer 类中的 replace and indexOf 方法(^_^ 故意凑方法),代码如下:

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public String deleteCharString9(String sourceString, char chElemData) {
String tmpString = "";
tmpString += chElemData;
StringBuffer stringBuffer = new StringBuffer(sourceString);
int iFlag = -1;
do {
iFlag = stringBuffer.indexOf(tmpString);
if (iFlag != -1) {
stringBuffer = stringBuffer.replace(iFlag, iFlag + 1, "");
}
} while (iFlag != -1);
return stringBuffer.toString();
}

第十一种方法

采用 stringBuffer 类中的 deleteCharAt 和 indexOf 直接删除

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public String deleteCharString10(String sourceString, char chElemData) {
String tmpString = "";
tmpString += chElemData;
StringBuffer stringBuffer = new StringBuffer(sourceString);
int iFlag = -1;
do {
iFlag = stringBuffer.indexOf(tmpString);
if (iFlag != -1) {
stringBuffer.deleteCharAt(iFlag);
}
} while (iFlag != -1);
return stringBuffer.toString();
}

程序运行截图:

image

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