


PHP uses an array to replace the matching items in the string in sequence, and the php array replaces the string
Let’s first look at a sql statement:
select * from table where ctime >= '[date-14]' and ctime <= '[date-1]';
I want to replace the dates represented by square brackets in the above SQL statement with the elements in the array below: array('2015-07-01','2015-07-15');
Use regular matching: find the first square bracket part, replace it with the first element, then find the second one, and replace it
Use sprintf function: Because the dates have been calculated, just replace them in order.
Because it is troublesome to write regular expressions in markdown, I will upload pictures directly here
ps: Imagine that if there is only one time condition in SQL that needs to be replaced, it needs to be modified to
$sql = sprintf($sql,$arr[0])
To put it bluntly, it would be great if the sprintf function supports the second parameter being an array. After some research, there is indeed a solution:
call_user_func_array() The official explanation is:
call_user_func_array — Call the callback function and pass an array parameter as the parameter of the callback function
mixed call_user_func_array ( callable $callback , array $param_arr )
Call the first parameter as the callback function (callback), and pass in the parameter array (param_arr) as the parameters of the callback function.
That is to say: the first parameter is the name of the function you want to use (sprintf above), and the second parameter is the parameter of the function to be used, but the parameters are passed to call_user_func_arrayok in the form of an array, so If so, dynamic replacement can be achieved
$param = $arr; array_unshift($param,$sql); $sql = call_user_func_array('sprintf',$param);
Next, we will introduce str_replace — substring replacement, array replacement
Description
mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )
This function returns a string or array. This string or array is the result of replacing all search in subject with replace.
If you have some special replacement requirements (such as regular expressions), you should use this function to replace ereg_replace() and preg_replace().
Parameters
If search and replace are arrays, str_replace() will perform mapping replacement on subject. If the number of replace values is less than the number of search values, additional replacements will be performed using empty strings. If search is an array and replace is a string, then the replacement of each element in search will always use this string. This conversion does not change case.
If search and replace are both arrays, their values will be processed sequentially.
search
The target value to find, which is needle. An array can specify multiple targets.
replace
Replacement value for search. An array can be used to specify multiple replacements.
subject
Array or string to perform replacement. That is haystack.
If subject is an array, the replacement operation will traverse the entire subject and the return value will also be an array.
count
Note: If specified, it controls the number of matches and replacements.
Return value
This function returns the replaced array or string.
Version Description
5.0.0 adds count parameter.
4.3.3 Function behavior changes. There is a BUG in the old version - when both parameters of search and replace are arrays, the empty search index will be skipped, but the internal pointer of replace will not be advanced at the same time. This error occurs in PHP
4.3.3, any scripts that depend on this bug should first remove empty lookup values to simulate the original behavior.
4.0.5 Most parameters can be arrays.
Example
Example #1 str_replace() basic example
<?php // 赋值: <body text='black'> $bodytag = str_replace("%body%", "black", "<body text='%body%'>"); // 赋值: Hll Wrld f PHP $vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U"); $onlyconsonants = str_replace($vowels, "", "Hello World of PHP"); // 赋值: You should eat pizza, beer, and ice cream every day $phrase = "You should eat fruits, vegetables, and fiber every day."; $healthy = array("fruits", "vegetables", "fiber"); $yummy = array("pizza", "beer", "ice cream"); $newphrase = str_replace($healthy, $yummy, $phrase); // 赋值: 2 $str = str_replace("ll", "", "good golly miss molly!", $count); echo $count; ?>
Example #2 Possible str_replace() replacement example
<?php // 替换顺序 $str = "Line 1\nLine 2\rLine 3\r\nLine 4\n"; $order = array("\r\n", "\n", "\r"); $replace = '<br />'; // 首先替换 \r\n 字符,因此它们不会被两次转换 $newstr = str_replace($order, $replace, $str); // 输出 F ,因为 A 被 B 替换,B 又被 C 替换,以此类推... // 由于从左到右依次替换,最终 E 被 F 替换 $search = array('A', 'B', 'C', 'D', 'E'); $replace = array('B', 'C', 'D', 'E', 'F'); $subject = 'A'; echo str_replace($search, $replace, $subject); // 输出: apearpearle pear // 由于上面提到的原因 $letters = array('a', 'p'); $fruit = array('apple', 'pear'); $text = 'a p'; $output = str_replace($letters, $fruit, $text); echo $output; ?>
Notes
Note: This function is safe to use on binary objects.
Caution
Learn the substitution order
Since str_replace() is replaced from left to right, previously inserted values may be replaced when performing multiple replacements. See this document for examples.
Note:
This function is case-sensitive. Case-insensitive replacement is possible using str_ireplace().
Articles you may be interested in:
- php Separate strings into string arrays by capital letters
- Concatenate one-dimensional or multi-dimensional arrays into a string PHP code
- PHP function to convert strings separated by commas, spaces, and carriage returns into arrays
- PHP implementation method of converting arrays and strings into each other
- Based on common PHP functions Summary (array, string, time, file operation)
- A summary of PHP’s array and string conversion functions
- Function in PHP that converts an array into a string and saves it to the database Code
- Use the explode function in php to split strings into arrays
- php example of converting two-dimensional arrays into strings
- php determines whether a string exists in an array element Method
- PHP method to randomly split a string into arrays of different lengths
- PHP method to convert multi-dimensional array to string and multi-dimensional array to one-dimensional array

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 English version
Recommended: Win version, supports code prompts!

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)
