Cho một chuỗi và một chuỗi con, hãy viết chương trình Python để tìm lần xuất hiện thứ n của chuỗi. Hãy thảo luận về một vài phương pháp để giải quyết nhiệm vụ nhất định.
Nhận lần xuất hiện thứ N của chuỗi con trong Chuỗi bằng regex
Ở đây, chúng tôi tìm thấy chỉ mục của ký tự 'ab' ở vị trí thứ 4 bằng cách sử dụng regex re. công cụ tìm[]
Python3
Nth occurrence is at 621
Nth occurrence is at 622
Nth occurrence is at 623
Nth occurrence is at 624
Nth occurrence is at 625
Nth occurrence is at 626
Nth occurrence is at 60____125
Nth occurrence is at 62
Nth occurrence is at 63____125
Nth occurrence is at 65
Nth occurrence is at 66
Nth occurrence is at 67
Nth occurrence is at 625
Nth occurrence is at 69
Nth occurrence of substring at 60
Nth occurrence of substring at 61
Nth occurrence of substring at 62
Nth occurrence of substring at 63
Nth occurrence is at 62
Nth occurrence of substring at 65
Nth occurrence of substring at 66
Nth occurrence of substring at 67
Nth occurrence of substring at 68
Nth occurrence is at 625
Nth occurrence is at 65
Nth occurrence is at 671
Nth occurrence is at 672
Nth occurrence is at 672
Nth occurrence is at 674
Nth occurrence is at 672
Nth occurrence is at 676
Nth occurrence is at 677____178
Nth occurrence is at 679
Nth occurrence is at 6210
Nth occurrence is at 6211
Nth occurrence is at 6212
Nth occurrence is at 6213
Nth occurrence is at 671
Nth occurrence is at 672
Nth occurrence is at 676
Nth occurrence is at 677____1218
Nth occurrence is at 6219
Nth occurrence is at 6220
Nth occurrence is at 6221
đầu ra
Nth occurrence of substring at 6
Nhận lần xuất hiện thứ N của chuỗi con trong Chuỗi bằng phương thức find[]
Ở đây, chúng tôi tìm thấy chỉ số của ký tự 'ab' ở vị trí thứ 4 bằng cách sử dụng str. tìm thấy[]
Python3
Nth occurrence is at 623
Nth occurrence is at 624
Nth occurrence is at 625
Nth occurrence is at 626
Nth occurrence is at 6226
Nth occurrence is at 625
Nth occurrence is at 62
Nth occurrence is at 63____125
Nth occurrence is at 65
Nth occurrence is at 66
Nth occurrence is at 6233
Nth occurrence is at 625
Nth occurrence is at 6210
Nth occurrence is at 6211
Nth occurrence of substring at 60
Nth occurrence is at 6238
Nth occurrence of substring at 62
Nth occurrence is at 6240
Nth occurrence is at 677
Nth occurrence is at 6242
Nth occurrence is at 6243
Nth occurrence is at 672
Nth occurrence is at 6233
Nth occurrence is at 625
Nth occurrence is at 6247
Nth occurrence is at 6248
Nth occurrence is at 6211
Nth occurrence is at 6250
Nth occurrence is at 672
Nth occurrence is at 6252
Nth occurrence is at 676
Nth occurrence is at 677____1255____1256
đầu ra
Nth occurrence is at 6
Nhận lần xuất hiện thứ N của một chuỗi con trong Chuỗi bằng cách sử dụng startedwith[]
Ở đây, chúng tôi tìm thấy chỉ số của ký tự 'ab' ở vị trí thứ 4 bằng cách sử dụng str. bắt đầu với[]
Python3
Nth occurrence is at 623
Nth occurrence is at 624
Nth occurrence is at 625
Nth occurrence is at 626
Nth occurrence is at 60____125
Nth occurrence is at 62
Nth occurrence is at 63____125
Nth occurrence is at 65
Nth occurrence is at 66
Nth occurrence is at 67
Nth occurrence is at 625
Nth occurrence is at 600
Nth occurrence of substring at 60
Nth occurrence is at 6238
Nth occurrence of substring at 62
Nth occurrence is at 6240
Nth occurrence is at 677
Nth occurrence is at 6242
Nth occurrence is at 607
Nth occurrence of substring at 67
Nth occurrence is at 609
Nth occurrence is at 610
Nth occurrence of substring at 66
Nth occurrence is at 612
Nth occurrence of substring at 66
Nth occurrence of substring at 67
Nth occurrence of substring at 68
Nth occurrence is at 625
Nth occurrence is at 65
Nth occurrence is at 671
Nth occurrence is at 672
Nth occurrence is at 672
Nth occurrence is at 674
Nth occurrence is at 672
Nth occurrence is at 676
Nth occurrence is at 677____178
Nth occurrence is at 679
Nth occurrence is at 6210
Nth occurrence is at 6211
Nth occurrence is at 6212
Nth occurrence is at 6213
Nth occurrence is at 671
Nth occurrence is at 672
Nth occurrence is at 676
Nth occurrence is at 677____1218
Nth occurrence is at 6219
Nth occurrence is at 6220
Nth occurrence is at 6221
Nth occurrence is at 639
đầu ra
Nth occurrence of substring at 6
Nhận lần xuất hiện thứ N của chuỗi con trong Chuỗi bằng cách sử dụng split[]
Ở đây, chúng ta tìm chỉ mục của ký tự ‘ab’ ở vị trí thứ 4 bằng cách sử dụng hàm split[]
Python3
Nth occurrence is at 640
Nth occurrence is at 641
Nth occurrence is at 642
Nth occurrence is at 643
Nth occurrence is at 644
Nth occurrence is at 645
Nth occurrence is at 625
Nth occurrence is at 647
Nth occurrence is at 642
Nth occurrence is at 649
Nth occurrence is at 644
Nth occurrence of substring at 66
Nth occurrence of substring at 67
Nth occurrence is at 653
Nth occurrence is at 625
Nth occurrence is at 655
Nth occurrence is at 656
Nth occurrence is at 657
Nth occurrence is at 6210
Nth occurrence is at 6211
Nth occurrence is at 644
Nth occurrence is at 657
Nth occurrence of substring at 67
Nth occurrence is at 663
Nth occurrence is at 6210
Nth occurrence of substring at 67
Nth occurrence is at 666
Nth occurrence is at 6210
Nth occurrence is at 6211
Nth occurrence is at 6212
Nth occurrence is at 6210
Nth occurrence of substring at 67
Nth occurrence is at 677
Nth occurrence is at 642
Nth occurrence is at 6250
Nth occurrence is at 676
Nth occurrence is at 677____077
Nth occurrence is at 607
Nth occurrence of substring at 67
Nth occurrence is at 677______081
Nth occurrence is at 682
Nth occurrence is at 676
Nth occurrence is at 677_______085
Nth occurrence is at 686
Nth occurrence is at 681
Nth occurrence is at 607____089
Nth occurrence is at 607
Nth occurrence is at 691
Nth occurrence is at 682
Làm thế nào chúng ta có thể tìm thấy sự xuất hiện của một ký tự trong một chuỗi trong PHP?
Hàm PHP substr_count[]
. Ghi chú. Chuỗi con phân biệt chữ hoa chữ thường.
Strstr PHP là gì?
Hàm strstr[] tìm kiếm sự xuất hiện đầu tiên của một chuỗi bên trong một chuỗi khác . Ghi chú. Hàm này an toàn nhị phân. Ghi chú. Hàm này phân biệt chữ hoa chữ thường. Đối với tìm kiếm không phân biệt chữ hoa chữ thường, hãy sử dụng hàm stristr[].
Làm cách nào tôi có thể nhận được 3 ký tự đầu tiên của chuỗi trong PHP?
Để lấy n ký tự đầu tiên của một chuỗi, chúng ta có thể sử dụng hàm substr[] tích hợp sẵn trong PHP . Đây là một ví dụ, lấy 3 ký tự đầu tiên từ một chuỗi sau.
Strpos trả về gì trong PHP nếu không tìm thấy?
Trả về vị trí nơi kim tồn tại so với phần đầu của chuỗi đống cỏ khô [không phụ thuộc vào độ lệch]. Cũng lưu ý rằng các vị trí chuỗi bắt đầu từ 0 chứ không phải 1. Trả về false nếu không tìm thấy kim.