# Conditional Statements

Sometimes you have to take actions based on the user's input or maybe you have to run a block of code based on conditions, in that case, we can use conditional statements.

There are 4 types of conditional statements :

### **if statement**

it is used to execute a block of code only if the condition is true.

**Syntax:**

```javascript
if (condition ===true){
//block of code to be executed
}
```

**Example:**

```javascript
if (age>=18){
console.log("you can drive")
}
```

### **if-else statements**

it is used to execute a block of code if you don’t know whether the condition is true or false. It helps you run two different blocks of code based on their boolean value.

**Syntax:**

```javascript
if (condition===true){
//code to be executed
}

else{
//code to be executed
}
```

**Example:**

```javascript
let time = 5 

if (time>=20){
console.log("good night")
}

else{
console.log("good morning")
}
```

### **if- else if-else statements**

It is used to check multiple conditions and only executes the block whose boolean value is true. If all conditions are false then it runs the else block of code.

**Syntax:**

```javascript
if (condition===true){
//code to be executed
}

else if (condition===true){
//code to be executed
}

else{
//code to be executed
}
```

**Example:**

```javascript
let time=10

if (time<12){
console.log("Good Morning")
}

else if (time>=12 && time <16){
console.log("Good Afternoon")
}

else if (time>=16 && time <=20){
console.log("Good Evening")
}

else if (time>20 && time <=24){
console.log("Good Night")
}

else{
console.log("you have entered the wrong time")
}
```

### **switch statements**

A switch statement can replace multiple if checks. It gives a more descriptive way to compare a value with multiple variants.

**Syntax:**

```javascript
switch(x) {
  case 'value1':  // if (x === 'value1')
     //code to be executed 
    break;

  case 'value2':  // if (x === 'value2')
    //code to be executed
    break;

  default:
    //code to be executed
    break;
}
```

**Example:**

```javascript
let a = 2 + 2;

switch (a) {
  case 1:
    alert( 'Too small' )
    break;
  case 2:
    alert( 'Exactly!' )
    break;
  case 3:
    alert( 'Too big' )
    break;
  default:
    alert( "I don't know such values" )
    break;
}
```