Convert String to Number in C
1. Using Built-in Functions:
- Use the built-in function to convert the string to a number.
#include <stdio.h>
#include <stdlib.h>
int main()
{
char str[] = "123";
// Step 1
int num = atoi(str);
printf("%d\n", num);
return 0;
}
Output
123
2. String Concatenation:
- Check if the string represents a negative number and set a flag.
- Iterate over each character of the string and convert it to its corresponding numerical value.
- Calculate the numerical value using the digits.
#include <stdio.h>
int main()
{
char str[] = "-123";
int i = 0, sign = 1, num = 0;
// Step 1
if (str[0] == '-') {
sign = -1;
i++;
}
// Step 2
while (str[i] != '\0') {
num = num * 10 + (str[i] - '0');
i++;
}
// Step 3
num *= sign;
printf("%d\n", num);
return 0;
}
Output
-123
How to Convert String to Number
Given a string representation of a numerical value, convert it into an actual numerical value. In this article, we will provide a detailed overview about different ways to convert string to number in different languages.
Table of Content
- Convert String to Number in C
- Convert String to Number in C++
- Convert String to Number in Java
- Convert String to Number in Python
- Convert String to Number in C#
- Convert String to Number in JavaScript