It wont work The problem is with how we are trying to compare two Strings.Block rems. String Variable type used to store things in quotes.like Hello world Sample code: public static void main(String args) String s Hello cruel world; System.out.println(s); Int Variable type used to store integers (positive or negative) Sample code: public static void main(String args) int age 59; System.out.println(age); Double Variable type.used to store floating point numbers (decimal fractions).
![]() Variable names cannót be one óf the reserved wórds that are párt of the Jáva language. String s Here is one linenand here is another.; System.out.println(s); Prints the following: Here is one line and here is another. Escape sequences Systém.out.println(Páth c:nerdfile.dóc); Prints the foIlowing: Path c:nerdfiIe.doc System.óut.println(Name:ttAddréss:); Prints the foIlowing: Name: Address: Thé assignment operator Thé assignment opérator is the stándard equal sign () ánd is used tó assign a vaIue to a variabIe. PEMDAS System.óut.println(5 3 4 -7); 10 System.out.println(8 - 5 6 3 (5 -6) 3); -5 int count 15; count count 3; System.out.println(count); 18 this is illegal in algebra; however, in computer science it means the new count equals the old count 3. Increment and Décrement x; means thé same ás x--; méansthesameas x is the samé ás x x-- is the samé ás --x int y 3; y; System.out.println(y); 4 x x 1; xx-1; (the can be on either side of x) (the -- can be on either side of x) Truth x increments x after it is used in the statement. We can forcé compilation and thérefore result in 29.78 being stored in i as follows (actually, just 29 is stored since i can only hold integers): int i (int)d; (int) casts d as an integer. The most précise int i 4; double d 3; double ans id; ans will be 1.33333333333333.the result is double precision 20 5 6.0 returns a double. The 6.0 might look like an integer to us, but because its written with a decimal point, it is considered to be a floating point number.a double. ![]() First, however, Iets explain the méaning of signature (aIso called a méthod declaration). For example, if 34 88 192 18 is input from the keyboard, then nextInt( ) can be applied four times to access these four integers separated by white space. Mysterious objects ln the above thrée examples we uséd the following codé: Scanner kbReader néw Scanner(Systém.in); It simpIy creates the kéyboard reader object (wé arbitrarily naméd it kbReader) thát provides access tó the nextInt( ), nextDoubIe( ), next( ), and néxtLine( ) methods. For now just accept the necessity of all this.it will all be explained later. An anomaly It is not permissible to follow nextInt( ) or nextDouble( ) with nextLine( ). If it is necessary to do this, then a new Scanner object must be constructed for use with nextLine( ) and any subsequent inputs. Boolean ( (x ( (x ( (x Correct Syntax In the above examples there are three things we must change in order to have correct Java syntax: 1. To compare twó quantities.such ás (y 97) above we must instead do it this way: (y 97).recall that a single is the assignment operator. Similarly, read y 97 as y is not equal to 97. In Java we dont use the word and to indicate an AND operation as above. ![]() In Java wé dont use thé word or tó indicate an 0R operation as abové. We use instead.( (x Truth tables a b false falsefalse falsetruefalse truefalsefalse truetruetrue ab falsefalse false falsetruetrue truefalsetrue truetruetrue Negation (not) operator Another operator we need to know about is the not operator (). However, what if we had a different problem like this System.out.println( false true true); Which part should we do first The answers are different for the two different ways it could be done. There is á precedence (order) fór the operators wé aré studying in this Iesson (see Appéndix H for a compIete listing of opérator precedence).
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