متد ()startsWith در کلاس String جاوا

خلاصه مطلب

در این جلسه آموزشی قصد داریم به بررسی متد ()startsWith یکی از متدهای موجود در کلاس String بپردازیم.

نوع محتوامقاله آموزشی

موضوعآموزش برنامه نویسی »

زمان مطالعه۱ دقیقه مطالعه

آخرین ویرایش۳ آبان ۱۳۹۶

کلاس String https://jadvalyab.ir/fa2en/پیشوند

a1="java";a2="javalike";

a1="like"; a2="javalike";

String a1 = "javapro.ir";

String a2 = "javapro";

String a1 = "Java Tutorial for Complete Beginners";

String a2 = "Java Tutorial";

boolean startsWith(String str):

1. package javalike; 2. public class StartsWithMethodExample { 3. public static void main(String args[]) { 4. String str1 = "Java Tutorial for Complete Beginners"; 5. String str2 = "Java Tutorial"; 6. System.out.println(str1.startsWith(str2)); 7. System.out.println(str1.startsWith("for Complete")); 8. System.out.println(str1.startsWith("Java")); 9. System.out.println(str1.startsWith("Ja")); 10. System.out.println(str1.startsWith("J")); 11. System.out.println(str1.startsWith("Tutorial")); 12. System.out.println(str1.startsWith("Beginners")); 13. } 14. }

true false true true true false false

boolean startsWith(String str, intfromindex)

String a="java like Tutorial";

String str="like Tutorial";

a.startsWith(str, 5)

a.startsWith(str, n)

String a="javalike"; String str="like";

1. package javalike; 2. public class TestStartsWith { 3. public static void main(String[] args) { 4. String a = "javalike"; 5. String str = "like"; 6. System.out.println(a.startsWith(str, 4)); 7. } 8. }

true

package javalike;public class TestStartsWith { public static void main(String[] args) { String a = "javalike"; String str = "like"; System.out.println(a.startsWith(str, 0)); } }

false

package javalike;public class StartsWithExample { public static void main(String args[]) { String str = new String("quick brown fox jumps over the lazy dog"); System.out.println("String str starts with quick: "+ str.startsWith("quick")); System.out.println("String str starts with brown: "+ str.startsWith("brown")); System.out.println("substring of str(starting from 6th index) has brown prefix: " + str.startsWith("brown", 6)); System.out.println("substring of str(starting from 6th index) has quick prefix: " + str.startsWith("quick", 6)); } }

String str starts with quick: true String str starts with brown: false substring of str(starting from 6th index) has brown prefix: true substring of str(starting from 6th index) has quick prefix: false

String str = new String("quick brown fox jumps over the lazy dog"); System.out.println("String str starts with quick: " + str.startsWith("quick"));

System.out.println("String str starts with brown: " + str.startsWith("brown"));

System.out.println("substring of str(starting from 6th index) has brown prefix: "+ str.startsWith("brown", 6));