---

Compare and Logical operators in C

---

• Compare operators in C
  • Fact:

    Compare operators in C behave the same way as those in Java.... But you need to know how interpret true and false The compare operators in C and Java are the "same" if you interpret the result of the compare operators as follows: 1 to represent true 0 to represent false

    ---

  • Summary of the compare operators in C

    Compare operations | Meaning ---------------------+----------------------------------------------------- x == y | returns 1 if x is equals to y, returns 0 otherwise x != y | returns 1 if x is not equals to y, returns 0 otherwise x < y | Ditto: less than x <= y | Ditto: less than or equal x > y | Ditto: greater than x >= y | Ditto: greater than or equal

  ---

  ---

  ---

  ---

• Logical operators in C
  • Fact:

    Logical operators in C behave the same way as those in Java.... if you interpret the result of the compare operators as follows: 1 to represent true 0 to represent false

    ---

  • Summary of the logical operators in C

    Compare operations | Meaning ---------------------+----------------------------------------------------- x && y | returns 1 if "x and y" is true, returns 0 otherwise x || y | Ditto: logical or !x | Ditto: logical not

    ---

    ---

  • Examples:

    #include <stdio.h> int main( int argc, char* argv[] ) { printf("4 == 3 = %d\n", (4==3) ); printf("4 > 3 = %d\n", (4 > 3) ); printf("4 && 3 = %d\n", (4 && 3) ); printf("4 && 0 = %d\n", (4 && 0) ); printf("4 || 0 = %d\n", (4 || 0) ); printf("0 || 0 = %d\n", (0 || 0) ); }

    Output:

    4 == 3 = 0 4 > 3 = 1 4 && 3 = 1 4 && 0 = 0 4 || 0 = 1 0 || 0 = 0

  • Example Program: (Demo above code)                                                
    • Prog file: /home/cs255001/demo/C/set1/logic2.c

    How to run the program:

    To compile:   gcc logic2.c          To run: ./a.out

  ---

  ---

  ---

  ---

• Summary
  • Compare operators ( < , <= , > , >= , == , != ) and logical operators (&& , || , ! ) in C will

    return the int value 1 if the result is true return the int value 0 if the result is false