If statement

• syntax: if ( <expression> ) <statement>

• semantic: if <expression> is nonzero (true), then <statement> is executed; otherwise is skipped

  • example: if (grade >= 90)
    printf("congratulations!\n");
    printf("your grade is %d.\n",grade);
  • short circuit evaluation: if (0 && b < c)

• if-else statement

  • example: if (x < y) min = x;
    else min = y;
  • Nested if and if-else statement
    • "dangling else" problem
      if (a == 1) if (a == 1)
      if (b == 2) { if (b == 2)
      printf("***\n"); printf("***\n"); }
      else printf("###\n") else printf("###\n")

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