Write a program to convert string to number without using Integer.parseInt() method


Levels of difficulty: / perform operation:

Below example shows how to convert string format of a number to number without calling Integer.parseInt() method. We can do this by converting each character into ascii format and form the number.

Program

package com.java2novice.algos;
public class MyStringToNumber {
	public static int convert_String_To_Number(String numStr) {
		char ch[] = numStr.toCharArray();
		int sum = 0;
		//get ascii value for zero
		int zeroAscii = (int)'0';
		for (char c:ch) {
			int tmpAscii = (int)c;
			sum = (sum*10)+(tmpAscii-zeroAscii);
		}
		return sum;
	}
	public static void main(String a[]) {
		System.out.println("\"3256\" == "+convert_String_To_Number("3256"));
		System.out.println("\"76289\" == "+convert_String_To_Number("76289"));
		System.out.println("\"90087\" == "+convert_String_To_Number("90087"));
	}
}

Output

“3256″ == 3256
“76289″ == 76289
“90087″ == 90087






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