C Program to Display Prime Numbers Between Two Intervals Using Functions - Source Code, Output & Execution Flow

C Programs

C Program to Display Prime Numbers Between Two Intervals Using Functions

This C program displays prime numbers in a range using a reusable prime-checking function.

#include <stdio.h>
int isPrime(int n) {
    int i;
    if (n <= 1) return 0;
    for (i = 2; i * i <= n; i++) if (n % i == 0) return 0;
    return 1;
}
int main() {
    int low, high, i;
    printf("Enter two intervals: ");
    scanf("%d %d", &low, &high);
    printf("Prime numbers: ");
    for (i = low; i <= high; i++) if (isPrime(i)) printf("%d ", i);
    printf("
");
    return 0;
}
Enter two intervals: 10 30
Prime numbers: 11 13 17 19 23 29

In this program, the input is read first when required, the core logic is applied step by step, and the final result is displayed using printf(). Follow the execution flow beside the code to understand how each statement contributes to the output.


C Programs❯

  1. 1Top 100 C Programs with Examples and Explanations
  2. 2C Hello World Program
  3. 3C Program to Print Your Own Name
  4. 4C Program to Print an Integer Entered by the User
  5. 5C Program to Add Two Numbers
  6. 6C Program to Check Whether a Number is Prime or Not
  7. 7C Program to Multiply Two Floating‑Point Numbers
  8. 8C Program to Print the ASCII Value of a Character
  9. 9C Program to Swap Two Numbers
  10. 10C Program to Calculate Fahrenheit to Celsius
  11. 11C Program to Find the Size of int, float, double and char
  12. 12C Program - Add Two Complex Numbers
  13. 13C Program - Print Prime Numbers From 1 to N
  14. 14C Program - Find Simple Interest
  15. 15C Program - Find Compound Interest
  16. 16C Program - Area And Perimeter Of Rectangle
  17. 17C Program - Check Whether a Number is Positive, Negative, or Zero
  18. 18C Program - Check Whether Number is Even or Odd
  19. 19C Program - Check Whether a Character is Vowel or Consonant
  20. 20C Program - Find Largest Number Among Three Numbers
  21. 21C Program - Calculate Sum of Natural Numbers
  22. 22C Program - Print Alphabets From A to Z Using Loop
  23. 23C Program - Check Leap Year
  24. 24C Program - Find Factorial of a Number
  25. 25C Program - Make a Simple Calculator
  26. 26C Program - Generate Multiplication Table
  27. 27C Program - Print Fibonacci Series
  28. 28C Program - Find LCM of Two Numbers
  29. 29C Program - Check Armstrong Number
  30. 30C Program - Display Armstrong Numbers Between 1 to 1000
  31. 31C Program - Display Armstrong Number Between Two Intervals
  32. 32C Program - Reverse a Number
  33. 33C Program - Check Whether a Number is a Palindrome or Not
  34. 34C Program - Display Prime Numbers Between Intervals
  35. 35C Program - Check whether the input number is a Neon Number
  36. 36C Program - Find All Factors of a Natural Number
  37. 37C Program - Print Simple Pyramid Pattern
  38. 38C Program - Print Given Triangle
  39. 39C Program - Print 180° Rotation of Simple Pyramid
  40. 40C Program - Print Inverted Pyramid
  41. 41C Program - Print Number Pattern
  42. 42C Program to Print Character Pattern
  43. 43C Program to Print Hollow Star Pyramid
  44. 44C Program to Print Pascal's Pattern Triangle Pyramid
  45. 45C Program to Print Floyd's Pattern Triangle Pyramid
  46. 46C Program to Check Prime Number By Creating a Function
  47. 47C Program to Display Prime Numbers Between Two Intervals Using Functions
  48. 48C Program to Find All Roots of a Quadratic Equation
  49. 49C Program to Check Whether a Number can be Express as Sum of Two Prime Numbers
  50. 50C Program to Find the Sum of Natural Numbers using Recursion
  51. 51C Program to Calculate the Factorial of a Number Using Recursion
  52. 52C Program to Find G.C.D Using Recursion
  53. 53C Program to Calculate Power Using Recursion
  54. 54C Program to Print a 2D Array
  55. 55C Program to Find the Largest Element in an Array
  56. 56C Program to Find the Maximum and Minimum in an Array
  57. 57C Program to Search an Element in an Array (Binary search)
  58. 58C Program to Calculate the Average of All the Elements Present in an Array
  59. 59C Program to Sort an Array using Bubble Sort
  60. 60C Program to Sort an Array using Merge Sort
  61. 61C Program to Sort an Array Using Selection Sort
  62. 62C Program to Sort an Array Using Insertion Sort
  63. 63C Program to Sort the Elements of an Array in Descending Order
  64. 64C Program to Sort the Elements of an Array in Ascending Order
  65. 65C Program to Remove Duplicate Elements From a Sorted Array
  66. 66C Program to Merge Two Arrays
  67. 67C Program to Find Common Array Elements
  68. 68C Program to Copy All the Elements of One Array to Another Array
  69. 69C Program to Array Rotation
  70. 70C Program to Sort the 2D Array Across Rows
  71. 71C Program to Check Whether Two Matrices Are Equal or Not
  72. 72C Program to Find the Transpose
  73. 73C Program to Find the Determinant of a Matrix
  74. 74C Program to Find the Normal and Trace
  75. 75C Program to Add Two Matrices
  76. 76C Program to Multiply Two Matrices
  77. 77C Program to Print Boundary Elements of a Matrix
  78. 78C Program to Rotate Matrix Elements
  79. 79C Program to Compute the Sum of Diagonals of a Matrix
  80. 80C Program to Interchange Elements of First and Last in a Matrix Across Rows
  81. 81C Program to Add or Concatenate Two Strings
  82. 82C Program to Add 2 Binary Strings
  83. 83C Program to Get a Non-Repeating Character From the Given String
  84. 84C Program to Check if the string is palindrome or not
  85. 85C Program to Reverse an Array or String
  86. 86C Program to Reverse a String Using Recursion
  87. 87C Program to Find the Length of a String
  88. 88C Program to Sort a String
  89. 89C Program to Check For Pangram String
  90. 90C Program to Print the First Letter of Each Word
  91. 91C Program to Remove Leading Zeros
  92. 92C Program to Compute Quotient and Remainder
  93. 93C Program to Demonstrate the Working of Keyword long
  94. 94C Program to Check Whether a Character is an Alphabet or not
  95. 95C Program to Count Number of Digits in an Integer
  96. 96C Program to Calculate the Power of a Number
  97. 97C Program to Reverse a Sentence Using Recursion
  98. 98C Program to Calculate Standard Deviation
  99. 99C Program to Multiply two Matrices by Passing Matrix to a Function
  100. 100C Program to Swap Numbers in Cyclic Order Using Call by Reference
  101. 101C Program to Remove all Characters in a String Except Alphabets
  102. 102C Character Pattern Program
  103. 103C Hollow Star Pyramid Pattern
  104. 104C Floyd's Triangle Program
  105. 105C Pascal's Triangle Program
  106. 106C Prime Number Check using Function
  107. 107C Prime Numbers in Range using Functions