Shartli o’tish operatorlari C++ kursi uchun ma'ruza

Shartli o’tish operatorlari

C++ kursi uchun ma'ruza

Tanlov konstruksiyalari

C ++ quyidagi shartli iboralarga ega:

• if Agar belgilangan shart rost bo'lsa, bajarilishi kerak bo'lgan kod blokini belgilash uchun foydalaning
• Else Agar bir xil shart noto'g'ri bo'lsa, bajarilishi kerak bo'lgan kod blokini belgilash uchun foydalaning
• else if Agar birinchi shart noto'g'ri bo'lsa, sinov qilish uchun yangi shartni belgilash uchun foydalaning
• Switch Amalga oshiriladigan ko'plab alternativ kod bloklarini belgilash uchun foydalaning

IF (Agar)

• If sintaksisi
• E'tibor bering, if kichik harflar bilan. Katta harflar (If yoki IF) xato keltirib chiqaradi.

if ()
{ // Faqat to'g'ri bo'lgandagi holatni yozasiz
}

if bayonoti

Mantiqiy ifoda to'g'ri yoki noto'g'ri bo'lgan shartni ifodalaydi.

U operandlar (doimiylar, o'zgaruvchilar) va operatorlar (arifmetik operatorlar, relyatsion operatorlar, mantiqiy operatorlar) yordamida tuziladi.

• Operatorlar:
•  
• Misol uchun,

if ((x > 0) && (a == b)) …

Arifmetik	taqqoslash	Mantiqiy
+ -	< kichik > katta	|| yoki
* / %	== teng != teng emas	&& va
Arifmetik funksiyalar	<= kichik yoki teng >= katta yoki teng	! emas

Operatorning ustuvorligi

Operator	Associativity	Type
( )	L  R	parenthesis
++ – – + – !	R  L	unary operators
* ? %	L  R	multiplicative
+ –	L  R	additive
<< >>	L  R	insertion
< <= > >=	L  R	relational
= = !=	L  R	equality
&&	L  R	and
||	L  R	or
?:	R  L	conditional
= += –= *= /= %=	R  L	assignment

If / else

• if/else sintaksisi
• if <mantiqiy ifoda> <amal1> [else <amal2>];
• Misol: Agar talabning bahosi 60 dan yuqoti bo’lsa imtihondan o’tdi aks holda o’tolmadi.
• C++:

if (grade >= 60)

cout << “Passed”;

else

cout << “Failed”;

If / else - shart operatorining qisqa ko’rinishi

C++ shartli operatori ternar operatori ->?:

Sintaksis:

o'zgaruvchi= (shart) ? shart to'g'ri bo'lsa:  shart notug'ri bo'lsa;

• Misol:

grade>=60? cout << “Passed” : cout << “Failed”;

• yoki:

cout << (grade >=60? “Passed” : “Failed”);

3 ta sondan kattasini topuvchi dastur

// Finding the largest of 3 values

#include

 

int main(){

int A, B, C, max;

 

cout << "Enter 3 values, and I will tell you which is largest.\n";

cin >> A >> B >> C; //really should have user prompts here

if (A > B)

max = A;

else

max = B;

if (C > max)

max = C;

cout << "The maximum is " << max << endl;

return 0;

}

Ichma ich joylashgan if

// Ushbu dastur test ballini harf bahosiga aylantiradi.

#include

int main(){

int score;

cout << "Enter the test score: "; cin >> score;

if (score > 100) cout << "Error: score is out of range." ;

else if (score >= 90) cout << 'A';

else if (score >= 80) cout << 'B';

else if (score >= 70) cout << 'C';

else if (score >= 60) cout << 'D';

else if (score >= 0) cout << 'F';

else

cout <<"Error: score is out of range.";

return 0;

}

C++ Switch (Tanlash Operatori)

Sintaksisi:

switch(qiymat) {

case x: // code block break;

case y: // code block break;

default: // code block }

Bu quyidagicha ishlaydi:

• switchIfoda bir marta baholanadi
• Ifodaning qiymati har birining qiymatlari bilan taqqoslanadi case
• Agar mos keladigan bo'lsa, tegishli kod bloki bajariladi
• break tanlash operatorini ishini yakunlaydi
• defaultkalit so'zlar ixtiyoriy bo'lgan qiymat uchun ishlaydi. yuqoridagi birontasi mos kelmasi demak default ishlaydi

.

Switch

Ushbu dastur ham test ballini harf bahosiga aylantiradi.

#include

int main(){

int score;

cout << "Enter the test score: ";

cin >> score;

switch (score/10) {

case 10:

case 9: cout << 'A' << endl; break;

case 8: cout << 'B' << endl; break;

case 7: cout << 'C' << endl; break;

case 6: cout << 'D' << endl; break;

case 5:

case 4:

case 3:

case 2:

case 1:

case 0: cout << 'F' << endl; break;

default: cout << "Error: score is out of range.\n";

}

return 0; }