How to convert string to number in PHP

PHP method to convert a string into a number: 1. Use the number_format function to convert the string into a number; 2. Use type conversion to directly convert the string into a basic type such as float; 3. Use functions such as intval Convert; 4. Convert by adding 0 or performing mathematical operations.

The operating environment of this article: Windows 7 system, Dell G3 computer, PHP version 7.1.

Strings in PHP can be easily converted to numbers (float/int/double). In most use cases it is not necessary as PHP performs implicit type conversions. There are many ways to convert strings to numbers in PHP.

The following introduces you to four methods of converting strings into numbers in PHP.

Method 1:

Use the number_format() function. The number_format() function is used to convert string to number. It returns a formatted number on success, otherwise gives E_WARNING on failure.

<?php 
  
$num = "1000.314"; 
  
// 使用number_format()函数将字符串转换为数字
echo number_format($num), "\n"; 
  
// 函数的作用是:将字符串转换为数字
echo number_format($num, 2); 
?>

Output:

1,000
1,000.31

Method 2:

Use type conversion: Type conversion can directly convert the string to float, double or integer basically type. This is the best way to convert string to number without using any function.

Example:

<?php 
  
// 字符串格式的数字 
$num = "1000.314"; 
  
// 使用int类型转换
echo (int)$num, "\n"; 
  
// 使用float 类型转换 
echo (float)$num, "\n"; 
  
// 使用double 类型转换
echo (double)$num; 
?>

Output:

1000
1000.314
1000.314

Method 3:

Use intval() and floatval() functions. The intval() and floatval() functions can also be used to convert strings to their corresponding integer and floating point values ​​respectively.

Example:

<?php 
  
// 字符串格式的数字 
$num = "1000.314"; 
  
// intval函数的作用是:将字符串转换为整数
echo intval($num), "\n"; 
  
// floatval函数的作用是:将字符串转换为浮点数
echo floatval($num); 
?>

Output:

1000
1000.314

Method 4:

By adding 0 or performing mathematical operations. It is also possible to convert a string number to an integer or floating point number by adding 0's to the string. In PHP, strings are implicitly converted to integers or floats when performing mathematical operations.

<?php 
      
// 数字转换成字符串格式
$num = "1000.314"; 
  
// 对隐式类型转换执行数学运算 
echo $num + 0, "\n"; 
  
// 对隐式类型转换执行数学运算
echo $num + 0.0, "\n"; 
  
// 对隐式类型转换执行数学运算
echo $num + 0.1; 
?>

Output:

1000.314
1000.314
1000.414

This article is an introduction to the four methods of converting strings into numbers in PHP. It is simple and easy to understand. I hope it will be helpful to friends in need!

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