CSC 107 – Programming For Science

Today’s Goal  Discover best uses of structures in a program  Using typedef to make meaningful names

Creating A struct

Using structs

Assigning struct s  Like all variables, can assign struct s  Identical struct type needed for source & target  Works like assigning fields in source to fields in target  Primitive values are copied like primitive variables  With assignment, arrays & pointers alias same value  Fields just like variables of the same type  Can be used just like any variable of that type  Need struct to get access to the field initially

Pointers to struct

typedef s For Simplicity  Make synonyms for types using a typedef: typedef original type new_name;  Simplify & clarify code by making types meaningful  Synonym only for coder; computer ignores difference  Really creates shorthand; does NOT make new type typedef long BIG_INTEGER; typedef unsigned long bob; typedef char * CSTRING; typedef struct energy ENERGY;

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Will It Compile? typedef int MIDDLE; typedef char* CSTRING; typedef struct energy ENERGY; MIDDLE i = 5; CSTRING str = “Bob”; struct energy ball; ENERGY *nerf = &ball; int j = i; strcpy(str, “Yo, whatup dog”); nerf = new struct energy[100]; i++; str = new CSTRING[23]; nerf = new ENERGY[12]; nerf[2] = ball; str = new char[42];

Your Turn  Get into your groups and try this assignment

For Next Lecture  Spend 1 last day on struct s on Wednesday  Write better solution to well-known problem  Understand why struct s used in real-world problems  Before moving on in class, solidify students knowledge  Angel has Weekly Assignment #12 for Tuesday  Last programming assignment  Last programming assignment due next week