Less Than or Equal To Operator (`<=`) in C++

The less than or equal to operator in C++ is used to compare two values and checks if the left operand is less than or equal to the right operand. It returns a Boolean value:

true if the condition holds.
false otherwise.

Syntax

operand1 <= operand2

1. Integer Comparison

lte_int_true.cpp

int a = 5, b = 10;
std::cout << (a <= b);  // Output: 1 (true)

lte_int_equal.cpp

int a = 10, b = 10;
std::cout << (a <= b);  // Output: 1 (true)

lte_int_false.cpp

int a = 20, b = 10;
std::cout << (a <= b);  // Output: 0 (false)

2. Float and Double Comparison

lte_float_true.cpp

float x = 3.5f, y = 4.2f;
std::cout << (x <= y);  // Output: 1 (true)

lte_double_equal.cpp

double x = 7.77, y = 7.77;
std::cout << (x <= y);  // Output: 1 (true)

lte_float_false.cpp

float a = 9.5f, b = 4.5f;
std::cout << (a <= b);  // Output: 0 (false)

3. Character Comparison

Characters are compared based on their ASCII values.

lte_char_true.cpp

char a = 'a', b = 'z';
std::cout << (a <= b);  // Output: 1 (true)

lte_char_equal.cpp

char x = 'm', y = 'm';
std::cout << (x <= y);  // Output: 1 (true)

lte_char_false.cpp

char a = 'z', b = 'x';
std::cout << (a <= b);  // Output: 0 (false)

4. Boolean Comparison

lte_bool.cpp

bool a = false, b = true;
std::cout << (a <= b);  // Output: 1 (true)

lte_bool_equal.cpp

bool a = true, b = true;
std::cout << (a <= b);  // Output: 1 (true)

lte_bool_false.cpp

bool a = true, b = false;
std::cout << (a <= b);  // Output: 0 (false)

5. String Comparison (`std::string`)

lte_string_true.cpp

std::string a = "apple";
std::string b = "banana";
std::cout << (a <= b);  // Output: 1 (true)

lte_string_equal.cpp

std::string a = "hello";
std::string b = "hello";
std::cout << (a <= b);  // Output: 1 (true)

lte_string_false.cpp

std::string a = "zebra";
std::string b = "apple";
std::cout << (a <= b);  // Output: 0 (false)

6. C-Style String Comparison

Use strcmp() for comparing character arrays:

lte_cstring.cpp

#include <cstring>
char a[] = "apple";
char b[] = "banana";
std::cout << (strcmp(a, b) <= 0);  // Output: 1 (true)

7. Usage in Conditional Statements

lte_if.cpp

int score = 55;
if (score <= 60) {
    std::cout << "Needs improvement";
}

8. Usage in Loops

lte_loop.cpp

for (int i = 1; i <= 5; i++) {
    std::cout << i << " ";
}

Output: 1 2 3 4 5

9. Mixed Data Type Comparison

lte_mixed.cpp

int a = 10;
float b = 10.0f;
std::cout << (a <= b);  // Output: 1 (true)

lte_mixed_false.cpp

double a = 7.5;
int b = 5;
std::cout << (a <= b);  // Output: 0 (false)

10. Practice Programs

Practice 1: Age Eligibility

practice_lte_age.cpp

int age = 17;
if (age <= 18) {
    std::cout << "Eligible for student discount.";
}

Practice 2: Compare Float Grades

practice_lte_float.cpp

float grade1 = 85.5f;
float grade2 = 90.0f;
if (grade1 <= grade2) {
    std::cout << "Grade1 is lower or equal.";
}

Practice 3: Lexicographic Comparison

practice_lte_string.cpp

std::string word1 = "apple";
std::string word2 = "mango";
if (word1 <= word2) {
    std::cout << word1 << " comes before or is same as " << word2;
}

Summary Table

Data Type	Expression	Result
`int`	`5 <= 5`	`true`
`float`	`3.2f <= 4.0f`	`true`
`double`	`9.1 <= 8.5`	`false`
`char`	`'a' <= 'b'`	`true`
`bool`	`false <= true`	`true`
`std::string`	`"abc" <= "xyz"`	`true`
`char[]`	`strcmp("alpha", "beta") <= 0`	`true`

Key Takeaways

<= helps check whether a value is less than or equal to another.
It works with all basic data types and user-defined types like std::string.
For C-style strings, use strcmp() instead of <= directly.
Mixed-type comparisons (like int with float) are valid but involve implicit type conversion.
Often used in loops and conditionals for value bounds checking.

Greater than or Equal Logical AND

Less Than or Equal To Operator (<=) in C++