The difference between equal and double equal in C language

In C language, the difference between the "==" and "===" comparison operators is that "==" only compares values, while "===" compares both values ​​and types. Therefore, values ​​of different types may be equal when using "==", while using "===" will return true only if the value and type are equal.

The difference between "==" and "===" in C language

Question: What is the difference between the "==" and "===" operators in C language?

Answer: "==" and "===" are comparison operators in C language, but they have different behaviors:

"= ="operator

• #Compare values: Only compares the values ​​of two expressions, regardless of type.
• Result: Returns 0 (false) or 1 (true), indicating whether the values ​​of the two expressions are equal.

"===" operator

• Compare values ​​and types: Compare the values ​​of two expressions simultaneously and type.
• Result: Returns 0 (false) or 1 (true), indicating that the value and type of the two expressions are equal.

Example:

<code class="c">int a = 1;
double b = 1.0;

if (a == b) {
  // 值相等，无论类型不同
  printf("值相等\n");
}

if (a === b) {
  // 值和类型都相等
  printf("值和类型都相等\n");
}</code>

Usage difference:

• "==" is used to compare values equality, while "===" is used when both values ​​and types need to be considered the same.
• In most cases, using "==" is fine, but when it comes to comparing variables of different types or when exact type matching is required, "===" is useful.

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