Javascript common string judgment function code sharing_javascript skills

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/*
function obj$(id) Get the object based on id
function val$(id) Get the value of the object based on the id
function trim(str) Delete left and right spaces
function ltrim(str) Delete the left space
function rtrim (str) Delete the space on the right
function isEmpty(str) Whether the string has a value
function equals(str1, str2) js determines whether two strings are equal by comparing them
function equalsIgnoreCase(str1, str2) js determines whether two strings are equal regardless of case comparison
function isChinese(str) js determines whether it is Chinese
function isEmail(strEmail) js determines whether it is an email
function isImg(str) js determines whether it is a file in image format jpg|jpeg|swf|gif
function isInteger(str) js determines whether it is an integer
function isFloat                             js determines whether it is a floating point number
function isPost(str) js determines whether the postal code (1 to 6 digits)
function isMobile(str) js determines whether it is a mobile phone number
function isPhone(str) js determines whether it is a phone number. It must contain the area code and can contain the extension number
function isQQ(str) js determines whether the QQ number is legal or not
function isIP(str) js determines whether it is a legal IP
function isDate(str) js determines whether it is a date type (example: 2005-12-12)
function isIdCardNo(idNumber) js determines whether it is a legal ID number
*/
function obj$(id)
{
Return document.getElementById(id);
}
function val$(id)
{
var obj = document.getElementById(id);
If(obj !== null)
{ 
            return obj.value;                                  }  
Return null;
}
function trim(str)
{
Return str.replace(/(^s*)|(s*$)/g, '');
}
function ltrim(str)
{
Return str.replace(/^s*/g,'');
}
function rtrim(str)
{
Return str.replace(/s*$/,'');
}
function isEmpty(str)
{
If(str != null && str.length > 0)
{ 
         return true;                               }  
Return false;
}
function equals(str1, str2)
{
If(str1 == str2)
{ 
         return true;                               }  
    return false; 
} 
function equalsIgnoreCase(str1, str2) 
{ 
    if(str1.toUpperCase() == str2.toUpperCase()) 
    { 
        return true; 
    } 
    return false; 
} 
function isChinese(str) 
{ 
  var str = str.replace(/(^s*)|(s*$)/g,''); 
  if (!(/^[u4E00-uFA29]*$/.test(str) 
          && (!/^[uE7C7-uE7F3]*$/.test(str)))) 
  { 
      return false; 
  } 
  return true; 
} 
function isEmail(str) 
{ 
    if(/^[w-] (.[w-] )*@[w-] (.[w-] ) $/.test(str)) 
    { 
        return true
    } 
    return false; 
} 
function isImg(str) 
{ 
    var objReg = new RegExp("[.] (jpg|jpeg|swf|gif)$", "gi"); 
    if(objReg.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isInteger(str) 
{ 
    if(/^-?d $/.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isFloat(str) 
{ 
    if(/^(-?d )(.d )?$/.test(str) 
    { 
        return true; 
    } 
    return false; 
} 
function isPost(str) 
{ 
    if(/^d{1,6}$/.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isMobile(str) 
{ 
    if(/^1[35]d{9}/.test(str)) 
      { 
          return true; 
      } 
    return false; 
} 
function isPhone(str) 
{ 
    if(/^(0[1-9]d{1,2}-)d{7,8}(-d{1,8})?/.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isQQ(str){ 
    if(/^d{5,9}$/.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isIP(str){ 
    var reg = /^(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]).(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0).(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0).(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])$/; 
    if(.test(str)) 
    { 
        return true; 
    } 
    return false; 
} 
function isDate(str) 
{ 
    var reg = /^((((1[6-9]|[2-9]d)d{2})-(0?[13578]|1[02])-(0?[1-9]|[12]d|3[01]))|(((1[6-9]|[2-9]d)d{2})-(0?[13456789]|1[012])-(0?[1-9]|[12]d|30))|(((1[6-9]|[2-9]d)d{2})-0?2-(0?[1-9]|1d|2[0-8]))|(((1[6-9]|[2-9]d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))-0?2-29-))$/; 
    if(reg.test(str)) 
    { 
        return true; 
    } 
    return false;   
} 
function isIdCardNo(idNumber) 
{ 
    var factorArr = new Array(7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2,1); 
    var varArray = new Array(); 
    var lngProduct = 0; 
    var intCheckDigit; 
    var idNumber.length = ; 
    if ((idNumber.length != 15) && (idNumber.length != 18)) 
    { 
        return false; 
    }   
    for(i=0;i     { 
        varArray[i] = idNumber.charAt(i); 
        if ((varArray[i] < '0' || varArray[i] > '9') && (i != 17)) 
        { 
            return false; 
        } 
        else if (i < 17) 
        { 
            varArray[i] = varArray[i]*factorArr[i]; 
        } 
    } 
    if (idNumber.length == 18) 
    { 
        var date8 = idNumber.substring(6,14); 
        if (checkDate(date8) == false) 
        { 
            return false; 
        }       
        for(i=0;i<17;i ) 
        { 
            lngProduct = lngProduct varArray[i]; 
        }       
        intCheckDigit = 12 - lngProduct % 11; 
        switch (intCheckDigit) 
        { 
            case 10: 
                intCheckDigit = 'X'; 
                break; 
            case 11: 
                intCheckDigit = 0; 
                break; 
            case 12: 
                intCheckDigit = 1; 
                break; 
        }       
        if (varArray[17].toUpperCase() != intCheckDigit) 
        { 
            return false; 
        } 
    } 
    else
    {       
        var date6 = idNumber.substring(6,12); 
        if (checkDate(date6) == false) 
        { 
            return false; 
        } 
    } 
    return true; 
}

常见的字符串判断的函数基本上都涵盖在内了，小伙伴们根据自己的项目需求自由选择吧，如有遗漏的，还请给我留言，本文持续更新。