Find if a string begins with a specific set of characters in Arduino

The startsWith() function in Arduino helps you determine if a string starts with a specific set of characters. It returns true if the string starts with the substring you specified, else it returns false. An example implementation is given below −

Example

void setup() {    // put your setup code here, to run once:    Serial.begin(9600);    String String1 = "AB_Test";    String String2 = "CD_Test";    String substr1 = "AB";    String substr2 = "AB*";    if(String1.startsWith(substr1)){          Serial.print("String1 starts with substr1");       }    if(String2.startsWith(substr1)){          Serial.print("String2 starts with substr1");       }    if(String1.startsWith(substr2)){          Serial.print("String1 starts with substr2");       }    if(String2.startsWith(substr2)){          Serial.print("String2 starts with substr2");       } } void loop() {    // put your main code here, to run repeatedly }

As you can expect, this program will print "String1 starts with substr1" only. The corresponding Serial Monitor output is shown below (the garbage characters in the beginning are programming/ start-up noise) −

Output