String functions and operations
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This document discusses string functions in PHP programming. It defines what a string is, including that it is a collection of characters used to represent text. It then proceeds to describe several PHP functions for working with strings, including chr() and ord() to get character codes, strlen() to get string length, substr() to extract parts of a string, and trim() to remove whitespace. It provides syntax and examples for each function. The document concludes with some assignments asking the user to input strings and use the string functions.
String functions and operations
- 1. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org Hidaya Institute of Science & Technology www.histpk.org A Division of Hidaya Trust, Pakistan
- 2. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org String Functions and Operations
- 3. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org What Is String? A string is a data type used in programming, such as an integer and floating point unit, but is used to represent text rather than numbers. It is comprised of a set of characters that can also contain spaces and numbers. For example, the word "hamburger" and the phrase "I ate 3 hamburgers" are both strings. Even "12345" could be considered a string, if specified correctly. Typically, programmers must enclose strings in quotation marks for the data to recognized as a string and not a number or variable name. •String is a collection of characters. •String is a collection of ASCII characters.
- 4. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org PHP chr() Function The chr() function returns a character from the specified ASCII value. Syntax chr(ascii) Example <?php echo chr(65); echo chr(122); ?>
- 5. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org PHP ord() Function The ord() function returns the ASCII value of the first character of a string. Syntax ord(string) Example <?php echo ord(“h”).”<br />”; echo ord(“hello”).”<br />”; ?>
- 6. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org PHP strlen() Function The strlen() function is used to return the length of a string. Syntax strlen(string) Example <?php echo strlen("Hello world!"); ?>
- 7. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org PHP substr() Function The substr() function returns a part of a string. Syntax substr(string,start,length) Example <?php echo substr("Hello world!",6); echo substr("Hello world!",6,5); ?>
- 8. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org PHP trim() Function The trim() function removes whitespaces from both sides of a string. Syntax trim(string) Example <?php echo trim(“ Hello World ”); ?>
- 9. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org Assignment # 1 Enter String Text Click Output
- 10. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org Assignment # 2 Enter String Text Click Output
- 11. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org Assignment # 3 Enter String Text Click Output
- 12. © Copyright 2012 Hidaya Trust (Pakistan) ● A Non-Profit Organization ● www.hidayatrust.org / www,histpk.org Assignment # 4 Enter some text here Find character Replace character Click Output