StringBuilder public StringBuilder(String str) 构造一个初始化为指定字符串内容的字符串构建器。 字符串生成器的初始容量为16加上字符串参数的长度。 参数 str - 缓冲区的初始内容。 StringBuilder public StringBuilder(CharSequence seq) 构造一个字符串构建器,其中包含与指定的CharSequence相同的字符。
接收一个String对象作为参数,设置了value数组的初始容量为String对象的长度+16,并把String对象中的字符添加到value数组中 public StringBuilder(String str) { super(str.length() + 16);//此处同上 append(str);//本类中方法(下) } @Override public StringBuilder append(String str) { super.append(str);//...
public StringBuilder replace(int start, int end, String str) Replaces the characters in a substring of this sequence with characters in the specified String. The substring begins at the specified start and extends to the character at index end - 1 or to the end of the sequence if no such...
* index k in the new character sequence is equal to the character * at index k in the old character sequence, if k is less * than n; otherwise, it is equal to the character at index * k-n in the argument {@code str}. * * @param str a string. * @return a reference to this...
java如何把String转map java string转stringbuilder 1 String类的常用方法 说明: (1) 字符串str中字符的索引从0开始,范围为0到str.length()-1 (2) 使用indexOf进行字符或字符串查找时,如果匹配返回位置索引;如果没有匹配结果,返回-1 (3) 使用substring(beginIndex ,endIndex) 进行字符串截取时,包括beginIndex...
StringBufferappend(char[] str, int offset, int len) 将char数组参数的子阵列的字符串表示附加到此序列。从索引offset开始的char数组str按顺序附加到该序列的内容。 此序列的长度由的值增加len 。 str- 要附加的字符,offset-要追加的第一个字符的索引,len- 要追加的 char的数量。
java中StringBuffer与String、StringBuilder的区别 在java中我们经常可以看到StringBuffer和String的用法,但是我自己在使用过程中,经常会将两者弄混淆,今天我们就来了解一下两者的区别: 我们首先来看一下我们的官方API中的简单介绍: A string buffer islikeaString, but can be modified. At any point in time it ...
str String Returns Int32 Attributes RegisterAttribute Remarks Portions of this page are modifications based on work created and shared by theAndroid Open Source Projectand used according to terms described in theCreative Commons 2.5 Attribution License. ...
Then convert the string back into a string builder using the StringBuilder(String str) constructor. An Example The StringDemo program that was listed in the section titled "Strings" is an example of a program that would be more efficient if a StringBuilder were used instead of a String. ...
创建新对象,旧对象由java垃圾回收机制自动处理 sb = new StringBuilder(); 速度对比 测试1: // 循环次数:一千万次 final int loopTimes = 10000000; StringBuilder sb = new StringBuilder(); long begin = System.currentTimeMillis(); // 第3种方式 ...