Write a Java method getBinaryString(int toCalc) that takes as argument a (strictly) positive integer toCalc, and returns the binary representation of toCalc as a String. For instance, if toCalc = 13, the method should return the String "1101", since 13 = 1*2^3 + 1*2^2 + 0*2^1 + 1*2^0.

可以回答这个问题。下面是 Java 代码：

public static String getBinaryString(int toCalc) {
    if (toCalc == 0) {
        return "0";
    }
    StringBuilder sb = new StringBuilder();
    while (toCalc > 0) {
        sb.append(toCalc % 2);
        toCalc /= 2;
    }
    return sb.reverse().toString();
}