/*
ExpressionExample.java 
Examples of basic expressions in Java
 */
 
package pkg119_02_variables.variableEx;

public class ExpressionExample {

    public static void main(String[] args) {
 
        int x = 2;
        int y = 5;
        // evaluating expression
            // plug in variable values
            // order of operations
            // * / % left to right
            // + - left to right
        int z = 12 + 3 * y / 15 - x % 2;
            // 12 + 3 * 5 / 15 - 2 % 2
            // 12 + 15 / 15 - 2 % 2
            // 12 + 1 - 2 % 2
            // 12 + 1 - 0
            // 13 - 0
            // 13
            // result goes in z
        System.out.println(z);
        
        // precedence can be changed with parentheses
        x = (x + 7) * 3;
            // (2 + 7) * 3
            // 9 * 3
            // 27
            // result goes in x
        System.out.println(x);

        // increment and decrement
        x++; // same as x = x + 1
        y--; // same as y = y -1
        System.out.println(x);
        System.out.println(y);
        
        // more shortcuts
        x += 5;  // same as  x = x + 5
        y -= 5;  
        z *= 2; 
        x %= 2;
                
        
        // string concatenation
        String str = "hello";
        String str2 = " world";
        // + to stick strings together
        String hw = str + str2;
        System.out.println(hw);
        // can do right inside println
        System.out.println(str + str2);

        // no problem with str on both sides
        str = str + str2;
        System.out.println(str);
        // shortcut
        str += "!";
        System.out.println(str);
        
        
        // + for addition and concatenation
        int num = 12;
        String out = num + " is the answer";
            // 12 + " is the answer"
            // "12" + " is the answer"      -- int becomes String
            // "12 is the answer"
        System.out.println(out);
        
        // double quotes make a String literal
        // doesn't matter if string has name of variable in it
        // String literals do not get turned into variables!
        out = "num" + " is the answer";
            // "num is the answer"
        System.out.println(out);
        
        System.out.println(num + 1 + "is too big");
            // num + 1 + "is too big"
            // 12 + 1 + "is too big"
            // 13 + "is too big"
            // "13" + "is too big"
            // "13is too big"               -- if I don't put in space, no space
        
        System.out.println("just silly:" + num + 1);
            // "just silly:" + num + 1
            // "just silly:" + 12 + 1
            // "just silly:" + "12" + 1
            // "just silly:12" + 1
            // "just silly:12" + "1"
            // "just silly:121"

        
    }

    
}