A brief discussion on string object processing encountered in javascript

Parameter processing in javascript:

<script>
function getParam()
{
urlInfo=window.location.href; //获取当前页面的url
intLen=urlInfo.length; //获取url的长度
offset=urlInfo.indexOf("?"); //设置参数字符串开始的位置
strKeyValue=urlinfo.substr(offset,len); //取出参数字符串 这里会获得类似“id=1”这样的字符串
arrParam=strKeyValue.split("="); //对获得的参数字符串按照“=”进行分割
strParamValue=arrParam[1]; //得到参数值
alert("您要传递的参数值是"+strParamValue);
}
</script>

Properties of the String object in javascript:

length--returns the length of the string, not a function, no parentheses are required.

prototype--Add properties and methods

There are some functions for handling String objects in JavaScript:

concat() - Combine two or more characters of text and return a new string. (Basically, they are spliced ​​together by themselves)

charAt(a) - Returns the character a at the specified position. (It is rarely used, but I feel it is quite useful)

indexOf(a) - Returns the index of the first occurrence of a substring a in the string. If there is no match, it returns -1. (Frequently used)

lastIndexOf (a) - Returns the index of the last occurrence of a substring a in the string, or -1 if there is no match. (Frequently used)

match(reg) - Checks whether a string matches a regular expression reg. (Regular expressions have always been weak, take the time to learn them carefully)

substring(begin,end) - Returns a substring of the string, and the parameters include both ends. (Note that all are lowercase)

substr(start,length) - Returns the specified number of characters extracted from the string starting from the start subscript. (Do not confuse with the above one)

split(separator,howmany) - separator is a string or regular expression (required), howmany specifies the length of the returned array (optional) --- commonly used

replace(regexp/substr , replacement) - Replace characters (regularity is important)

toLowerCase() - Convert the entire string to lowercase letters.

toUpperCase() – Convert the entire string to uppercase letters.