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How to use PHP to convert the contents of a txt file into an array and obtain the specified content by line number (example)
How to use PHP to convert the contents of a txt file into an array and obtain the specified content by line number (example)
This article mainly introduces the method of PHP to read the contents of txt files into arrays and obtain specified data by row number. It can be used to realize paging display and storage of big data txt files, involving the operations of file_get_contents, explode and other functions in PHP. Tips and easy way to convert array of txt content. Friends in need can refer to it.
1. Introduction to functions related to PHP operating txt files
①About file_get_contents()
file_get_contents() function The file is read into a string.
The file_get_contents() function is the preferred method for reading the contents of a file into a string. If supported by the operating system, memory mapping technology is also used to enhance performance.
②About explode()
Explode-use one string to split another string
explode() function uses the specified delimiter to The string is broken into an array.
③About PHP for loop statement
For loop is one of the most commonly used loop statements in our work. No matter which language, there is this loop statement.
Grammar rules:
for (ex1; ex2; ex3){
Code to be executed
}
ex1: represents Where the loop starts
ex2: The condition of the loop. If the value is TRUE, the loop continues and the nested loop statement is executed. If the value is FALSE, the loop is terminated.
ex3: Evaluated (and executed) after each loop.
2: Specific method for PHP to read the contents of a txt file and convert it into an array and obtain the specified data by row number
Specific example The code is as follows:
<?php
$str = file_get_contents('url.txt'); //把url.txt文件中的内容读取到一个字符串中
$array = explode("\r\n",$str); //用换行的分割符（\r\n）把字符串分割成数组，即把每一行分割为数组的一个值
for($i=0;$i<200;$i++){
echo $array[$i];
echo "<br>";
} //用for循环语句输出url.txt文本中前200行内容，并用br标签换行展现
或for($i=0;$i<400;$i++){
echo $array[$i+200];
echo "<br>";} //输出url.txt文本中第200行至第400的内容
或echo $array[3]; //输出url.txt文本中第4行内容（数组的键值是从0开始的）
?>I hope this article will help you use a simple PHP method to obtain text specified content and implement paging display and saving of txt text.
【Recommended related articles】
PHP file processing—how to read a file (one line, the entire file)
PHP reading and paging txt text file
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php reading file -php introductory tutorial one, learn PHP in one week
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