Blog

Conditional Statements Kya Hote Hain?

Conditional statements programming me decision-making ke liye use hote hain, jisme ek condition check ki jati hai aur uske true ya false hone par specific code execute hota hai. Ye program ke flow ko control karte hain. if statement sirf true condition par code run karta hai, if-else dono cases handle karta hai, else-if  multiple conditions check karta hai, aur switch multiple cases ke liye use hota hai. Inka use program ko flexible aur interactive banata hai, jisse dynamic responses generate kiye ja sakte hain aur alag-alag situations ke according actions perform kiye ja sakte hain.

Common Conditional Statements in JavaScript:

• if statement
• if-else statement
• else-if ladder
• nested if statement
• switch statement

1. if Statement

if statement ka use tab hota hai jab ek condition satisfy hone par ek specific block of code execute karna ho. Agar condition true hai toh block of code chalega, warna nahi chalega.

if (condition) {
  // Yeh block sirf tab chalega jab condition true hogi
}

Example:

let temperature = 30;
if (temperature > 25) {
  console.log("Bahut garmi hai!");
}

Explanation :

Agar temperature 25 se zyada hai, toh “Bahut garmi hai!” print hoga. Agar temperature 25 se kam ya barabar hota, toh kuch nahi hota.

2. if-else Statement

Jab if condition false ho jaaye, tab else block execute hota hai. Isse humein ek alternative option milta hai.

if (condition) {
  // Jab condition true ho toh yeh chalega
} else {
  // Jab condition false ho toh yeh chalega
}

Example:

let temperature = 20;
if (temperature > 25) {
  console.log("Bahut garmi hai!");
} else {
  console.log("Mausam thoda thanda hai.");
}

Explanation :

Agar temperature > 25, toh “Bahut garmi hai!” print hoga.

Agar temperature <= 25, toh “Mausam thoda thanda hai.” print hoga.

3. else-if Ladder :

Jab multiple conditions ko check karna ho, tab else if ka use karte hain.

if (condition1) {
  // Condition1 true hone par yeh chalega
} else if (condition2) {
  // Agar condition1 false aur condition2 true hai toh yeh chalega
} else {
  // Jab koi bhi condition true nahi hoti tab yeh chalega
}

Example:

let marks = 75;
if (marks >= 90) {
  console.log("Aapko A+ grade mila.");
} else if (marks >= 80) {
  console.log("Aapko A grade mila.");
} else if (marks >= 70) {
  console.log("Aapko B grade mila.");
} else {
  console.log("Aapko Fail grade mila.");
}

Explanation :

Marks 90 ya zyada hone par “A+ grade” milega.

Marks 80 se 89 ke beech hone par “A grade” milega.

Marks 70 se 79 ke beech hone par “B grade” milega.

Marks 60 se 69 ke beech hone par “C grade” milega.

Agar marks 60 se kam hain, toh “Fail grade” milega.

4. Nested if Statement

Jab ek if statement ke andar ek aur if ya if-else statement hota hai, toh use nested if kahte hain.

if (condition1) {
  if (condition2) {
    // Jab dono conditions true ho tab yeh chalega
  }
}

Example:

let age = 20;
let hasVoterID = true;
if (age >= 18) {
  if (hasVoterID) {
    console.log("Aap vote de sakte hain.");
  } else {
    console.log("Pehle voter ID banwa lijiye.");
  }
} else {
  console.log("Aap vote nahi de sakte.");
}

Explanation :

Agar age 18 se zyada ya barabar hai, toh agla if check karega ki voter ID hai ya nahi.

Agar voter ID hai, toh “Aap vote de sakte hain.” print hoga.

Agar voter ID nahi hai, toh “Pehle voter ID banwa lijiye.” print hoga.

Agar age 18 se kam hai, toh “Aap vote nahi de sakte.” print hoga.

5. switch Statement

Jab ek variable ke multiple fixed values ko check karna ho, tab switch statement ka use hota hai. Yeh else if ka better alternative hai jab ek hi variable ke multiple values check karni ho.

switch (expression) {
  case value1:
    // Jab expression ka value1 se match hoga tab yeh chalega
    break;
  case value2:
    // Jab expression ka value2 se match hoga tab yeh chalega
    break;
  default:
    // Jab koi bhi case match nahi karega tab yeh chalega
}

Example:

let day = "Monday";
switch (day) {
  case "Sunday":
    console.log("Aaj Sunday hai, holiday!");
    break;
  case "Monday":
    console.log("Aaj Monday hai, kaam shuru karo!");
    break;
  default:
    console.log("Invalid din!");
}

Explanation :

Agar day = “Monday”, toh “Aaj Monday hai, kaam shuru karo!” print hoga.

break; ka use har case ke baad hota hai taki agla case execute na ho.

Agar koi bhi case match nahi karta, toh default block execute hoga.

Difference Between if-else and switch Statement

Conclusion

• if statement: Jab ek condition check karni ho.
• if-else statement: Jab ek condition false hone par kuch aur execute karna ho.
• else-if ladder: Jab multiple conditions check karni ho.
• nested if statement: Ek if ke andar ek aur if hota hai.
• switch statement: Jab ek variable ki multiple fixed values check karni ho.

Quiz: Test Your Knowledge on Conditional Statements in JavaScript

Bonus: Practical Application!

Aaj hi apne JavaScript code me Conditional Statements ka istemal karke dekhein!

Conditional Statements ko sahi tareeke se samajhne ke liye different types jaise if, else, else if, switch ka upayog karein aur apne JavaScript programs ko aur bhi dynamic banayein.