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