如何把字符串转化成整形 不用javaapi的方法
参考 ：http://blog.csdn.net/greatmind829/article/details/7870719
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public class Convert {?
?
??? public static void main(String[] args) {?
?????? Convert convert = new Convert();?
??????? int return_num = convert.convert_num("12345");?
??????? System.out.println("retunr nam --"+return_num);?
????????
??? }?
?????
??? /**
???? *? 把一组数字 字符串转化成数字
???? */?
?????
?? public int convert_num (String val){?
?????????
??????? int return_val = 0 ;?
?????? char[] char_arr = val.toCharArray();?
????
?????? for (int i = 0; i <char_arr.length; i++) {?
?????????? char c = char_arr[i];?
??????????? //例如： 100 = 10 *10???
??????????? int? val_v = (int)Math.pow(10, char_arr.length-(i+1));??
??????????? //在运算时char自动转换成 int类型的进行计算
??????????? return_val =? return_val + (c-48) *val_v;?
?????? }?
????? return return_val;?
??????? }?
}?
