First, you need a variable name in there for it to be legal. ? 1 2 1. String a = ""; 2. String b = null; Question: does line 2 initialize 'b' to an empty string? Line 1 create a String object and assigns it the reference 'a'. Line 2 only creates a reference( 'b' ) t...
// private final char value[];// public boolean isEmpty() { // return value.length == 0; // } /** Initializes a newly created object so that it represents an empty character sequence.*/ // public String() { // this.value = "".value; // } } } 1. 2. 3. 4. 5. 6. 7...
String substring(int beginIndex) String sustring(int beginIndex, int endIndex):返回一个新字符串,这个字符串包含原始字符串中从beginIndex到串尾或endIndex-1的所有代码单元。 String toLowerCase():返回一个新字符串,这个字符串将原始字符串中的所有大写字母改成了小写字母。 String toUpperCase():返回一个新字...
String(Byte[]) Constructs a new String by decoding the specified array of bytes using the platform's default charset. String(Char[], Int32, Int32) Initializes this string to contain the given chars. String(Char[]) Initializes this string to contain the given chars. String(Int32[], ...
* an empty character sequence. Note that use of this constructor is * unnecessary since Strings are immutable.*/publicString() {this.value = "".value; }/*** Initializes a newly created {@codeString} object so that it represents
String objectName =null;// apply naming strategyif( StringHelper.isEmpty( explicitName ) ) {// No explicit name given, so allow the naming strategy the chance// to determine it based on the corresponding mapped java nameobjectName = helper.determineImplicitName( getNamingStrategyDelegator() );...
Java中的String被设计为不可变的，这是出于一些原因和考虑：性能：不可变的字符串可以被缓存，因为它们的...
String() Initializes a newly created String object so that it represents an empty character sequence. String(byte[] bytes) Constructs a new String by decoding the specified array of bytes using the platform's default charset. String(byte[] ascii, int hibyte) Deprecated. This method doe...
publicstaticvoidmain(String[]args){ Integer integer=Integer.valueOf(1);inti=integer.intValue(); } int的自动装箱是通过Integer.valueOf()方法来实现的,Integer的自动拆箱都是通过integer.intValue来实现的。 其实自动装箱和自动拆箱是Java中的语法糖,用于简化基本数据类型和其对应包装类型之间的转换操作。当将基...
* Initializes a newly created {@code String} object so that it represents * an empty character sequence. Note that use of this constructor is * unnecessary since Strings are immutable. */ publicString() { this.value = new char[0]; ...