How to install jdk and fix javac cmd.

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+indexof(ch:char)

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Return type int. Returns the index of the first occurrence of ch in the string. Returns-1 if not matched. import java.lang.String; class indexof{                         public static void main(String[] args){                          String str="Welcome to java";                         int i="welcome".indexOf('l');                        System.out.println("Index of l in \" "+str+"\"  is : "+i);                      } } Output :    Index of l in "Welcome to java is : 2
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Data types and range in Java

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Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in memory. Based on the data type of a variable, the operating system allocates memory and decides what can be stored in the reserved memory. Therefore, by assigning different data types to variables, you can store integers, decimals, or characters in these variables. There are two data types available in Java: Primitive Data Types Reference/Object Data Types Primitive Data Types: There are eight primitive data types supported by Java. Primitive data types are predefined by the language and named by a keyword. Let us now look into detail about the eight primitive data types. byte: Byte data type is an 8-bit signed two's complement integer. Minimum value is -128 (-2^7) Maximum value is 127 (inclusive)(2^7 -1) Default value is 0 Byte data type is used to save space in large arrays, mainly in place of integers, since a...
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Immutable String and Interned Strings

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A String object is immutable; its contents cannot be changed. Does the following code change the contents of the string? String s = "Java"; s = "HTML"; The answer is no. The first statement creates a String object with the content “Java” and assigns its reference to s. The second statement creates a new String object with the con- tent “HTML” and assigns its reference to s. The first String object still exists after the assignment, but it can no longer be accessed, because variable s now points to the new object, as shown in Figure Since strings are immutable and are ubiquitous in programming, the JVM uses a unique instance for string literals with the same character sequence in order to improve efficiency and save memory. Such an instance is called interned. For example, the following statements: class immutable { public static void main(String[] arg) { String str1 = "Welcome to Smartprogrammeron.blogspot.in"; String str2 = new String("...
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