106 lines
2.4 KiB
Markdown
106 lines
2.4 KiB
Markdown
---
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title: C++ If Statement
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---
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# The IF statement.
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**What does an if statement do?**
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* The `if` statement evaluates the test expression present inside the parenthesis.
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* The `if` statement uses relational and logical operators to make logical expressions.
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-----------------------------------------------
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The general form of `if` statement:
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```cpp
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if (Test Expression / Condition)
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{
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// Block of statements if test expression is True
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}
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```
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If there is only one statement after the if statement the '{ }' are not necessarily required . But if there are more number of statements after if statement, then it is mandatory to put all those statements in '{}'.
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If the value of the test expression is **true**, then the block of
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code inside the if statement is executed.
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If the value of the test expression is **false**, then the block of
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code inside the if statement is skipped and your code continues.
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Example `if` statement:
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```cpp
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int a = 10;
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// true statement
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if (a < 20)
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{
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// execute this block of code
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}
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// false statement
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if (a < 0)
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{
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// Skip this block of code.
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}
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```
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Example In C++ :
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```cpp
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// Program to check if number entered by the user is positive
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// If negative, the block of code is skipped
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#include <iostream>
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using namespace std;
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int main()
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{
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int no ;
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cout << "Enter a number: ";
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cin >> no;
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// if statement to check if the number is positive
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if ( no > 0)
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{
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cout << "You have entered a positive number: " << no << endl;
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}
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// If number is not positive, then if statement is skipped a program continues
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cout << "This step is always printed" << endl;
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return 0;
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}
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```
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**Output:**
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OUTPUT 1:
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```
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Enter a number: 5
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You have entered a positive number: 5
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This step is always printed
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```
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This is the output when the number entered is positive.
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OUTPUT 2:
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```
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Enter a number: -1
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This step is always printed
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```
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This is the output when the number entered is negative.
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<a href='https://repl.it/Mg9X' target='_blank' rel='nofollow'>Try the code yourself ! :) </a>
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_CONGRATULATIONS . This is the end of the article on the IF statement_
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**Good Luck to all of you**
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**Happy Coding ! :)**
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**Feel free to ask any queries on FreeCodeCamp's GitHub page or [FreeCodeCamp's Forum .](https://forum.freecodecamp.org/)**
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