if, if ... else

if and else:

it used to check whether the given expression returns true or false and acts as such:

if (condition) statement

the condition can be any valid C++ expression that returns something that be checked against truth/falsehood for example:

if (true) { /* code here */ }  // evaluate that true is true and execute the code in the brackets
if (false) { /* code here */ } // always skip the code since false is always false

the condition can be anything, a function, a variable, or a comparison for example

if (istrue()) { } // evaluate the function, if it returns true, the if will execute the code
if (isTrue(var)) { } // evalute the return of the function after passing the argument var
if (a == b) { } // this will evaluate the return of the experssion (a==b) which will be true if equal and false if unequal
if (a) { } // if a is a boolean type, it will evaluate for its value, if it's an integer, any non zero value will be true,

if we want to check for a multiple expressions we can do it in two ways :

using binary operators :

if (a && b) { } // will be true only if both a and b are true (binary operators are outside the scope here
if (a || b ) { } //true if a or b is true

using if/ifelse/else:

for a simple switch either if or else

if (a == "test") {
    / /will execute if a is a string "test" 
} else {
    // only if the first failed, will execute 
}

for multiple choices :

if (a == 'a') {
  // if a is a char valued 'a'  
} else if (a == 'b') {
  // if a is a char valued 'b' 
} else if (a == 'c') {
  // if a is a char valued 'c'
} else { 
  //if a is none of the above
}

however it must be noted that you should use 'switch' instead if your code checks for the same variable's value

Found a mistake? Have a question or improvement idea? Let me know.

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