Just another update

Task/Variables/AWK/variables-1.awk

@@ -1,2 +1,20 @@
-a = 1               # Here we declare a numeric variable
-fruit = "banana"    # Here we declare a string datatype
+BEGIN {
+# Variables are dynamically typecast, and do not need declaration prior to use:
+  fruit = "banana"    # create a variable, and fill it with a string
+  a = 1               # create a variable, and fill it with a numeric value
+  a = "apple"         # re-use the above variable for a string
+  print a, fruit
+
+# Multiple assignments are possible from within a single statement:
+  x = y = z = 3
+  print "x,y,z:", x,y,z
+
+# "dynamically typecast" means the content of a variable is used
+# as needed by the current operation, e.g. for a calculation:
+  a = "1"
+  b = "2banana"
+  c = "3*4"
+
+  print "a,b,c=",a,b,c,  "c+0=", c+0, 0+c
+  print "a+b=", a+b, "b+c=", b+c
+}

Task/Variables/AWK/variables-2.awk

@@ -1 +1,7 @@
-x = y = z = 3
+# usage:  awk -v x=9  -f test.awk
+BEGIN {
+  y = 3
+  z = x+y
+  print "x,y,z:", x,y,z
+  printf( "x=%d,y=%d,z=%d:", x,y,z )
+}

Task/Variables/AWK/variables-3.awk

@@ -1,7 +1,15 @@
-function foo(j  k) {
-  # j is an argument passed from caller
-  # k is a dummy not passed by caller, but because it is in the
-  # argument list, it will have a scope local to the function
-  k = length(j)
-  print j "contains " k " characters"
+function foo(s,  k) {
+  # s is an argument passed from caller
+  # k is a dummy not passed by caller, but because it is
+  # in the argument list, it will have a scope local to the function
+  k = length(s)
+  print "'" s "' contains", k, "characters"
+}
+BEGIN {
+  k = 42
+  s = "Test"
+  foo("Demo")
+  print "k is still", k
+  foo(s,k)
+  print "k still is", k
 }

Task/Variables/AWK/variables-4.awk

@@ -0,0 +1,2 @@
+# Feeding standard-input with echo:
+echo -e "2 apples 0.44$ \n 3 banana 0.33$" | awk '{p=$1*$NF; sum+=p; print $2,":",p; }; END{print "Sum=",sum}'